Transportadora de Gas del Sur (TGS) 20-F 25 Apr 19 2018 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2018shares
Entity Information [Line Items]
Entity Registrant Name	GAS TRANSPORTER OF THE SOUTH INC
Entity Central Index Key	0000931427
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding	780,894,503
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Class "A" Shares [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	405,192,594
Class "B" Shares [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	389,302,689

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	[1]	Dec. 31, 2016	[1]
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Revenues		$ 34,062,670	$ 19,953,266		$ 14,645,510	[2]
Cost of sales		(16,188,310)	(11,935,682)		(10,025,424)	[2]
Gross profit		17,874,360	8,017,584		4,620,086	[2]
Administrative expenses		(961,813)	(733,874)		(880,767)	[2]
Selling expenses		(1,764,701)	(807,296)		(695,858)	[2]
Other operating expenses		(890,787)	(271,595)		(130,644)	[2]
Operating profit		14,257,059	6,204,819		2,912,817	[2]
Net financial results
Financial income		10,988,538	1,137,168		816,791	[2]
Financial expenses		(15,040,992)	(2,131,487)		(2,564,772)	[2]
Gain on net monetary position		1,206,195	465,975		1,038,647	[2]
Total		(2,846,259)	(528,344)		(709,334)	[2]
Share of profit from associates		18,207	21,641		5,089	[2]
Net income before income tax		11,429,007	5,698,116		2,208,572	[2]
Income tax (expense) / gain		(13,171)	53,077		(1,102,277)	[2]
Total comprehensive income for the year		11,415,836	5,751,193		1,106,295	[2]
Total comprehensive income attributable to:
Owners of the Company		11,415,832	5,751,191		1,106,293	[2]
Non-controlling interests		$ 4	$ 2		$ 2	[2]
Weighted average of outstanding ordinary shares (in shares)	[2]	788,405,563	794,495,283		794,495,283
Basic and diluted earnings per share (in pesos per share)		$ 14.48	$ 7.24		$ 1.39	[2]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL POSITION - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	[1]
Non-current assets
Property, plant and equipment	$ 38,685,519	$ 34,160,708
Investments in associates	72,670	55,924
Other financial assets at amortised cost	8,760	21,369
Deferred income tax asset	4,529	4,245
Other receivables	8,233	17,874
Trade receivables	0	4,511
Total non-current assets	38,779,711	34,264,631
Current assets
Other receivables	2,663,058	1,026,603
Inventories	360,274	183,745
Trade receivables	3,114,499	3,002,432
Contract assets	156,672	0
Derivative financial instruments	218,272	0
Other financial assets at amortised cost	5,714	2,134,111
Other financial assets at fair value through profit or loss	0	325,158
Cash and cash equivalents	16,644,827	3,916,747
Total current assets	23,163,316	10,588,796
Total assets	61,943,027	44,853,427
EQUITY
Common stock	18,347,477	18,667,034
Treasury shares	319,557	0
Cost of acquisition of treasury shares	(1,420,926)	0
Legal reserve	650,221	650,221
Future capital expenditures reserve	69,851	69,851
Future dividends reserve	991,627	1,557,240
Accumulated retained earnings	11,987,488	4,335,231
Non-controlling interests	10	12
Total equity	30,945,305	25,279,589
Non-current liabilities
Deferred income tax liabilities	2,228,094	6,460,995
Advances from customers	0	1,535,140
Contract liabilities	1,469,051	0
Loans	20,154,216	4,680,011
Total non-current liabilities	23,851,361	12,676,146
Current liabilities
Provisions	371,168	289,901
Contract liabilities	129,578	0
Advances from customers	0	216,820
Other payables	80,674	49,531
Taxes payables	202,222	142,562
Income tax payable	2,444,210	1,743,257
Payroll and social security taxes payable	383,636	347,274
Loans	442,836	1,962,609
Trade payables	3,092,037	2,145,738
Total current liabilities	7,146,361	6,897,692
Total liabilities	30,997,722	19,573,838
Total equity and liabilities	$ 61,943,027	$ 44,853,427
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - ARS ($) $ in Thousands	Total		Total attributable to equity holders [Member]		Shareholders Contributions, Total Common Stock [Member]		Shareholders Contributions, Common Stock [Member]		Shareholders Contributions, Inflation Adjustment to Common Stock [Member]		Shareholders Contributions, Treasury Shares, Common Stock [Member]		Shareholders Contributions, Treasury Shares, Inflation Adjustment to Common Stock [Member]		Acquisition Cost of Treasury Shares [Member]	[2]	Retained Earnings, Accumulated Retained Earnings [Member]		Retained Earnings, Legal Reserve [Member]		Retained Earnings, Future Dividend Reserve [Member]		Retained Earnings, Future Capital Expenditure Reserve [Member]		Retained Earnings, Subtotal [Member]		Non-Controlling Interests [Member]
Balance at beginning of period at Dec. 31, 2015	$ 18,649,007	[1]	$ 18,648,992	[1]	$ 18,667,034	[1]	$ 794,495	[1]	$ 17,872,539	[1]	$ 0	[1],[2]	$ 0	[1],[2]	$ 0		$ (1,313,105)	[1]	$ 613,770	[1]	$ 247,320	[1]	$ 433,973	[1]	$ (18,042)	[1]	$ 15	[1]
Resolutions of the Board of Director's Meeting
Cash dividends distribution	(226,899)		(226,899)		0		0		0								0		0		(226,899)		0		(226,899)		0
Resolutions of the Extraordinary and Ordinary Shareholders' Meeting
Future dividends reserve	0		0		0		0		0								(6,027)		0		0		6,027		0		0
Derecognition of Reserves	0		0		0		0		0								364,822		0		0		(364,822)		0		0
Comprehensive income for the year	1,106,295	[1],[3]	1,106,293		0		0		0		0		0		0		1,106,293		0		0		0		1,106,293		2
Balance at end of period at Dec. 31, 2016	19,528,403	[1]	19,528,386	[1]	18,667,034	[1]	794,495	[1]	17,872,539	[1]	0	[1],[2]	0	[1],[2]	0		151,983	[1]	613,770	[1]	20,421	[1]	75,178	[1]	861,352	[1]	17	[1]
Resolutions of the Extraordinary and Ordinary Shareholders' Meeting
Legal reserve	0		0		0		0		0								(36,451)		36,451		0		0		0		0
Future dividends reserve	0		0		0		0		0								(1,536,819)		0		1,536,819		0		0		0
Derecognition of Reserves	0		0		0		0		0								5,327		0		0		(5,327)		0		0
Cash dividends payment/distribution to non-controlling interest	(7)		0		0		0		0								0		0		0		0		0		(7)
Comprehensive income for the year	5,751,193	[1]	5,751,191		0		0		0		0		0		0		5,751,191		0		0		0		5,751,191		2
Balance at end of period at Dec. 31, 2017	25,279,589	[1]	25,279,577	[1]	18,667,034	[1]	794,495	[1]	17,872,539	[1]	0	[1],[2]	0	[1],[2]	0		4,335,231	[1]	650,221	[1]	1,557,240	[1]	69,851	[1]	6,612,543	[1]	12	[1]
Resolutions of the Board of Director's Meeting
Cash dividends distribution	(4,329,188)		(4,329,188)		0		0		0		0	[2]	0	[2]	0		0		0		(4,329,188)		0		(4,329,188)		0
Resolutions of the Extraordinary and Ordinary Shareholders' Meeting
Future dividends reserve	0		0		0		0		0		0	[2]	0	[2]	0		(3,763,575)		0		3,763,575		0		0		0
Treasury shares purchase	(1,420,926)		(1,420,926)		(1,420,926)		(13,601)		(305,956)		13,601	[2]	305,956	[2]	(1,420,926)		0		0		0		0		0		0
Cash dividends payment/distribution to non-controlling interest	(6)		0		0		0		0		0	[2]	0	[2]	0		0		0		0		0		0		(6)
Comprehensive income for the year	11,415,836		11,415,832		0		0		0		0	[2]	0	[2]	0		11,415,832		0		0		0		11,415,832		4
Balance at end of period at Dec. 31, 2018	$ 30,945,305		$ 30,945,295		$ 17,246,108		$ 780,894		$ 17,566,583		$ 13,601	[2]	$ 305,956	[2]	$ (1,420,926)		$ 11,987,488		$ 650,221		$ 991,627		$ 69,851		$ 13,699,187		$ 10
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	Corresponds to 13,600,780 shares of par value Ps. 1 each, equivalent to 1.71% of the share capital. The acquisition cost of these shares amounted to Ps. 1,420,926. See Note 19. c - Acquisition of treasury shares to the consolidated financial statements.
[3]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - Treasury Shares [Member] - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Shares issued (in shares)	13,600,780	0
Par value (in pesos per share)	$ 1
Percentage of share capital	1.71%
Acquisition cost	$ 1,420,926

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
CASH FLOWS PROVIDED BY OPERATING ACTIVITIES
Total comprehensive income for the year		$ 11,415,836	$ 5,751,193	[1]	$ 1,106,295	[1],[2]
Reconciliation of total comprehensive income to cash flows provided by operating activities:
Depreciation of property, plant and equipment		2,223,083	2,020,216	[1]	2,095,418	[1]
Derivative financial instrument results		(106,084)	0	[1]	9,383	[1]
Disposal of property, plant and equipment		158,516	131,419	[1]	16,368	[1]
Share of profit from associates		(18,207)	(21,641)	[1]	(5,089)	[1]
Increase in provisions		193,932	216,920	[1]	199,944	[1]
Interest expense accrual		1,588,977	728,644	[1]	857,402	[1]
Interest income on other financial assets other than cash and cash equivalents		(451,508)	(95,707)	[1]	(57,458)	[1]
Income tax		13,171	(53,077)	[1]	1,102,277	[1],[2]
Doubtful accounts		132,521	(23,395)	[1]	38,142	[1]
Foreign exchange loss		5,679,356	474,545	[1]	1,294,211	[1]
Gain on net monetary position		(3,852,871)	(866,188)	[1]	(1,605,917)	[1]
Changes in assets and liabilities:
Trade receivables		(1,486,325)	(1,402,841)	[1]	(970,984)	[1]
Other receivables		(783,827)	(374,555)	[1]	(555,537)	[1]
Inventories		(235,824)	9,748	[1]	(207,897)	[1]
Trade payables		1,611,499	360,635	[1]	907,752	[1]
Contract assets		(156,672)	0	[1]	0	[1]
Payroll and social security taxes payable		148,429	97,960	[1]	95,678	[1]
Taxes payables		49,972	10,920	[1]	(43,652)	[1]
Other payables		47,127	43,897	[1]	(68,416)	[1]
Provisions		437	(254,858)	[1]	(53,571)	[1]
Interest paid		(905,746)	(302,158)	[1]	(629,333)	[1]
Derivative financial instruments		(103,789)	0	[1]	238,432	[1]
Income tax paid		(2,777,871)	(833,558)	[1]	(19,502)	[1]
Contract liabilities		412,478	0	[1]	0	[1]
Advances from customers		0	(61,351)	[1]	382,267	[1]
Cash flows provided by operating activities		12,796,610	5,556,768	[1]	4,126,213	[1]
CASH FLOWS USED IN INVESTING ACTIVITIES
Additions to property, plant and equipment		(8,123,664)	(1,941,265)	[1]	(1,017,590)	[1]
Financial assets not considered cash equivalents		3,392,406	(1,936,424)	[1]	119,467	[1]
Cash flows used in investing activities		(4,731,258)	(3,877,689)	[1]	(898,123)	[1]
CASH FLOWS PROVIDED BY / (USED IN) FINANCING ACTIVITIES
Payment of loans		(1,226,061)	(59,876)	[1]	(1,772,017)	[1]
Precancellation of loans		(4,796,243)	0	[1]	0	[1]
Loans received		13,821,521	0	[1]	0	[1]
Payment of acquisition of treasury shares		(1,420,926)	0	[1]	0	[1]
Dividends paid		(4,329,188)	(6)	[1]	(226,899)	[1]
Cash flows provided by / (used in) financing activities		2,049,103	(59,882)	[1]	(1,998,916)	[1]
NET INCREASE IN CASH AND CASH EQUIVALENTS		10,114,455	1,619,197	[1]	1,229,174	[1]
Cash and cash equivalents at the beginning of the year	[1]	3,916,747	2,870,394		2,163,757
Foreign exchange gain on Cash and cash equivalents		6,687,668	225,006	[1]	176,765	[1]
Monetary results effect on Cash and cash equivalents		(4,074,043)	(797,850)	[1]	(699,302)	[1]
Cash and cash equivalents at the end of the year		$ 16,644,827	$ 3,916,747	[1]	$ 2,870,394	[1]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

BUSINESS DESCRIPTION

BUSINESS DESCRIPTION	12 Months Ended
	Dec. 31, 2018
BUSINESS DESCRIPTION [Abstract]
BUSINESS DESCRIPTION	1. BUSINESS DESCRIPTION Business Overview Transportadora de Gas del Sur S.A. (“TGS” or the “Company”) is one of the companies created as a result of the privatization of Gas del Estado S.E. (“GdE”). TGS commenced operations on December 29, 1992 and it is mainly engaged in the Transportation of Natural Gas, and Production and Commercialization of natural gas Liquids (“Liquids”). TGS’s pipeline system connects major natural gas fields in southern and western Argentina with natural gas distributors and industries in those areas and in the greater Buenos Aires area. The natural gas transportation license to operate this system was exclusively granted to TGS for a period of thirty-five years (“the License”). TGS is entitled to a one-time extension of ten years provided that it has essentially met the obligations imposed by the License and by the Ente Nacional Regulador del Gas On April 26, 2017, the Ordinary and Extraordinary Shareholders’ Meeting approved the amendment of TGS’ by-laws (the “Statutory Modification”) in order to: (i) expand the corporate purpose in order to incorporate the development of complementary, accessory, related and / or derived activities of natural gas transportation, such as the generation and sale of electricity and the provision of other services for the hydrocarbons sector in general, and (ii) the creation of an Executive Committee of the Board of Directors under the terms of Article 269 of the General Companies Law. The objective is to provide this Administration body with greater flexibility in decision-making. In relation to compliance with the regulatory requirements, it has been recorded that the Statutory Modification has not received comments from ENARGAS, in what concerns its competence, as informed by a note dated April 25, 2017, nor from (ii) the Comisión Nacional de Valores Major Shareholders TGS’s controlling shareholder is Compañía de Inversiones de Energía S.A. (“CIESA”), which holds 51% of the common stock. Local and foreign investors hold the remaining ownership of TGS’s common stock. CIESA is under co-control of: (i) Pampa Energía S.A. (“Pampa Energía”), which holds 10% of CIESA’s common stock, (ii) CIESA Trust (whose trustee is Pampa Energía and whose beneficiary is Petrobras Hispano Argentina SA, a wholly owned subsidiary of by Pampa Energía) (the “Trust”), who has a trust shareholding of 40% of the share capital of CIESA and (iii) Grupo Inversor Petroquímica S.L. (member of GIP Group, headed by Sielecki´s family; “GIP”), and PCT L.L.C. (“PCT”), which directly and together with WST S.A. (Member of Werthein Group, “WST”) indirectly through PEPCA S.A. (“PEPCA”), hold a 50% of the shareholding in CIESA in the following shares: GIP 27.10%, WST 4.58% and PCT 18.32%. The current shareholding structure of CIESA is the result of the exercise of the exchange contemplated in the transaction entered into between the current shareholders of the Company. This transaction was duly approved by ENARGAS on August 9, 2016 and December 29, 2016, by virtue of the different stages carried out until its final completion. On the other hand, by virtue of the acquisition made by Pampa Energía to an affiliate of Petróleo Brasileiro S.A., 100% of the share capital of Petrobras Participaciones S.L., controlling company of Petrobras Argentina S.A. (“Petrobras”) and consequently the indirect control of Petrobras Hispano Argentina SA, on February 16, 2017, the Extraordinary Shareholders’ Meetings of Pampa Energía and Petrobras approved the Prior Merger Commitment between Pampa Energía, as the absorbing company and Petrobras as absorbed company and the dissolution without liquidation of Petrobras. The merger was effective as from November 1, 2016, the date on which the transfer to the acquiring company of all the rights and obligations, assets and liabilities of the absorbed company takes effect. On April 26, 2018, the CNV notified the approval of the merger, which was registered in the Public Registry on May 2, 2018.

CONSOLIDATED FINANCIAL STATEMEN

CONSOLIDATED FINANCIAL STATEMENTS	12 Months Ended
	Dec. 31, 2018
CONSOLIDATED FINANCIAL STATEMENTS [Abstract]
CONSOLIDATED FINANCIAL STATEMENTS	2. CONSOLIDATED FINANCIAL STATEMENTS TGS presents its consolidated financial statements including a Telcosur S.A. (“Telcosur”) and CTG Energía S.A. (“CTG”), its consolidated subsidiaries, which are jointly referred to as “the Company”.

BASIS OF PRESENTATION

BASIS OF PRESENTATION	12 Months Ended
	Dec. 31, 2018
BASIS OF PRESENTATION [Abstract]
BASIS OF PRESENTATION	3. BASIS OF PRESENTATION These consolidated financial statements have been prepared in accordance with International Financial Reporting Standards issued by the International Accounting Standards Board (“IASB”) and the International Financial Interpretations Committee (“IFRIC”), jointly the “IFRS”. The preparation of the consolidated financial statements in conformity with IFRS requires management to make accounting estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, as well as the reported amounts of revenues and expenses during the reporting fiscal year. Estimates are used when accounting for the allowance for doubtful accounts, income taxes, provisions for legal claims and others, depreciation and recoverable value of assets. Actual results could be significantly different from such estimates. The presentation in the statement of financial position distinguishes between current and non-current assets and liabilities. The assets and liabilities are those expected to be realized or settled within twelve months after the end of the reporting period under review, and those held for sale. The fiscal year begins on January 1 and ends on December 31 of each year. The economic and financial results are presented on a fiscal year basis. The consolidated financial statements are stated in thousands of Argentine pesos (“Ps.” or “pesos”), which is the functional currency of the Company and its subsidiaries, unless otherwise stated. For further information, see Note 4.c.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2018
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	4. SIGNIFICANT ACCOUNTING POLICIES a) New accounting standards New standards and interpretations issued by the IASB effective for the periods beginning on or after January 1, 2018 adopted by the Company Below is a description of the standards, amendments and interpretations to existing standards that have been issued and were mandatory for the Company’s fiscal years beginning on or after January 1, 2018: IFRS 15 Revenue from contracts with customers In May 2014, IFRS 15 “Revenue from contracts with customers” was issued which establishes a new model for entities to account for revenue arising from contracts with customers. IFRS 15 will supersede the current revenue recognition guidance including IAS 18 “Revenue”, IAS 11 “Construction Contracts” and the related interpretations when it becomes effective. The Company adopted IFRS 15 using the modified retrospective method of adoption with the date of initial application of January 1, 2018. Accordingly, the Company elected to apply the standard to all outstanding contracts as at January 1, 2018. Therefore, the comparative information was not restated and continues to be reported under IAS 11, IAS 18 and related Interpretations. The core principle of IFRS 15 is that an entity shall assess the goods or services promised in a contract with a customer and shall identify its performance obligations. IFRS 15 introduces a 5-step approach to recognize revenue: Step 1: Identify the contract with a customer. Step 2: Identify the performance obligations in the contract. Step 3: Determine the transaction price. Step 4: Allocate the transaction price to the performance obligations in the contract. Step 5: Recognize revenue when (or as) the entity satisfies a performance obligation. The new revenue recognition model established in IFRS 15 is applicable to all contracts with customers, except other relevant IFRS rule applies such as for lease contracts, insurance contracts and financial instruments. Further, the recognition of interest and dividends are not under the scope of this standard. According to IFRS 15, among other issues, a mechanism is established for assigning the transaction price among the different performance obligations. According to this standard, the Company must recognize its income once the performance obligations are satisfied; this is whenever the “control” over the goods or services is transferred to the client. The standard specifies the accounting for the incremental cost of obtaining a contract with a customer and for the cost incurred to fulfill a contract with a customer. Note 8.i includes the main revenue streams of the Company. Given the analysis carried out by management, the Company has concluded that revenue recognition practices, in accordance with IAS 18, IAS 11 and related interpretations effective as of December 31, 2017, are consistent with IFRS 15 practices. Accordingly, the Company did not recognize any initial impact in its accumulated retained earnings as of January 1, 2018. The Company has made certain reclassifications on the statement of financial position in order to reflect classification and terminology used by IFRS 15. They correspond to the contract liabilities in relation to the advances from customers as prepayments for services to be rendered, which were previously presented as “Advances from Customers” line items (Ps. 1,751,960 as of January 1, 2018). The following table shows the impact in the Statement of Financial Position as January 1, 2018: Balances as of 31/12/2017 IFRS 15 impact Balances as of 01/01/2018 Current liabilities Advances from customers 216,820 (216,820) - Contract liabilities - 216,820 216,820 Total 216,820 - 216,820 Non current liabilities Advances from customers 1,535,140 (1,535,140) - Contract liabilities - 1,535,140 1,535,140 Total 1,535,140 - 1,535,140 The application of IFRS 15 has not had an impact on the accounting policies of the Company regarding the recognition of revenues of the different business segment. IFRS 9 Financial instruments IFRS 9 introduces new requirements to the classification and measurement of financial instruments, impairment and hedge accounting. IFRS 9 replaces, as from January 1, 2018, IAS 39 Financial Instruments: Recognition and Measurement, bringing together the three aspects of the accounting of financial instruments: classification and measurement; impairment; and hedge accounting. Given the analysis carried out by management, the Company did not record any adjustments to the accumulated earnings as of January 1, 2018, since the Company’s practices as of January 1, 2018 were consistent with IFRS 9. The Company made use of the exemption that allows it not to restate the comparative information of prior periods in relation to changes in classification and measurement (including impairment). As a result, the Company did not apply the requirements of IFRS 9 to the comparative periods presented. Thus, the comparative information as of December 31, 2017 and 2016 was not modified. a) Classification and measurement of financial assets and financial liabilities IFRS 9 largely retains the existing requirements in IAS 39 for the classification and measurement of financial liabilities. IFRS 9 introduces a new classification approach for financial assets, based on two concepts: the characteristics of the contractual cash flows of the financial asset and the company’s business model. The table below shows a comparison of the measurement criteria used for financial assets according to IAS 39, in contrast to the criteria used since the adoption of IFRS 9: Financial instrument Classification under IAS 39 Classification under IFRS 9 Cash and banks Loans and other receivables Amortized cost Mutual funds Fair value through profit or loss Fair value through profit or loss Bank accounts Loans and other receivables Amortized cost Government bonds (BONAR 2020) Fair value through profit or loss Fair value through profit or loss Private bonds Fair value through profit or loss Fair value through profit or loss Government bonds (LETES) Held to maturity Amortized cost Government bonds (Central Bank Notes) Held to maturity Amortized cost VRD bonds Loans and other receivables Amortized cost Trade receivables Loans and other receivables Amortized cost Other receivables Loans and other receivables Amortized cost b) Impairment of financial assets IFRS 9 replaces the ‘incurred loss’ model in IAS 39 with an “expected credit loss” (ECL) model. This requires considerable judgment to be applied with respect to how changes in economic factors affect ECL, which are determined on a weighted average basis. For further information, see “Note 4.e. – Financial Instruments and 4.h. Trade receivables and other receivables”. Given the nature of the clients with which TGS operates and its history of uncollectibility, the Company did not identify that the change in approach to the impairment method in accordance with that required by IFRS 9 results in the recognition of any adjustment to the balances at January 1, 2018 or 2018 transactions. In addition, in the case of financial investments and in accordance with current investment policies, the Company monitors the credit rating and the credit risk that these instruments have. Based on the analysis made, the Company did not identify that any adjustment should be made to the balances as of January 1, 2018 of said instruments. IFRIC 22 “Foreign Currency Transactions and Advance Consideration” This interpretation refers to the determination of the “transaction date” that determines the exchange rate to be used in the initial recognition of an asset, expense or income related to an entity that received or paid a foreign currency advance. Applies to foreign currency transactions when an entity recognizes a non-monetary asset or non-monetary liability arising from the receipt or payment of advance consideration before the entity recognizes the related asset, expense or income. For the purpose of determining the exchange rate to be used in the initial recognition of an asset, expense or income, the transaction date is the date on which the non-monetary asset or liability derived from the receipt or payment of the advance is recognized. The adoption of this standard has not had an impact on the financial position or on the results of the Company´s operations. Amendments to IAS 40 –Transfer of Investment Properties The amendments clarify that transfers to, or from, investment property can only be made if there has been a change in use that is supported by evidence. A change in use occurs when the property meets, or ceases to meet, the definition of investment property. A change in intention alone is not sufficient to support a transfer. The list of evidence for a change of use in the standard was re-characterised as a non-exhaustive list of examples to help illustrate the principle. The adoption of the amendment has not had an impact in the financial situation and results of operations of the Company as it has not held any investment property. New standards and interpretations issued by the IASB not yet effective for the period beginning on January 1, 2018 Below is a description of the standards, amendments and interpretations to existing standards that might impact the Company and are not mandatory for the Company’s fiscal years beginning on January 1, 2018 and which have not been early adopted by the Company: IFRS 16 “Leases” In January 2016, IFRS 16 “Leases” was issued which establishes a new model of accounting for leasing operations. This standard replaces the current guidance on the accounting for such operations in IAS 17 “Leases” and related interpretations. As a result of the modifications introduced, the accounting treatment of leases in the lessee accounting will undergo major changes. IFRS 16 eliminates the dual accounting model for lessee distinguishing between on-balance sheet finance leases and operating leases for which no recognition of future lease payments is required. Instead, a unique, in-balance model is developed that is similar to the current financial leasing model. There are certain exceptions for short-term and insignificant leases. It also requires the presentation of further disclosures. IFRS 16 is applicable for annual periods beginning after January 1, 2019. Adoption is retroactive. Given the analysis carried out by our management, it is not estimated that the application of IFRS 16 will have a significant impact on the accumulated results nor the financial position of the Company. IFRIC Interpretation 23 “Uncertainty over Income Tax Treatments” The interpretation clarifies the application of IAS 12 with regards to the effect of uncertain income tax position in tax gains (losses), tax base and unused tax losses / tax credits and tax rates. The interpretation specifically clarifies whether an entity should use judgment to determine each tax treatment independently or collectively. The decision should be based on which approach provides better predictions of the resolution of the uncertainty. An entity should assume that the relevant tax authority will review each tax treatment, or group of tax position and is fully aware of all the related information. • If the entity concludes that it is probable that a particular tax treatment is accepted, the entity has to determine taxable profit consistly with this tax treatment. • If the entity concludes that it is not probable that a particualr tax treatment is accpted, the entity has to use the most likely amount or the expected value of the tax treatment when determining taxable profit. The decision should be base on which method provides better predictions of the resolution of the uncertainty. IFRIC 23 is effective for annual periods beginning on or after January 1, 2019. Given the analysis carried out by our management, it is not estimated that the application of IFRIC 23 will have a significant impact on the accumulated results nor the financial position of the Company. Annual improvements to IFRS Standards 2015 – 2017 Cycle It includes amendments to IFRS 3 – Business combinations, IFRS 11 – Joint Arrangements, IAS 12 – Income tax and IAS 23 – Borrowing Costs. Regarding IAS 23 amendment clarifies that an entity treats as part of general borrowings any borrowing originally made to develop a qualifying asset when substantially all of the activities necessary to prepare that asset for its intended use or sale are complete. These amendments are effective for annual periods beginning on or after January 1, 2019. As they are accounting practices of the Company, no effect is expected on the financial statements. Amendments to IFRS 9 – Financial instruments The amendments introduced to IFRS 9, modify the application guide in relation to the classification of financial assets in the case of contractual terms that change the calendar or amount of contractual cash flows to determine whether the cash flows that could arise due to that condition are only payments of the principal and interests. When it is a condition that allows the issuer to pay (or allow the holder to repay) a debt instrument before maturity, it must be considered whether the anticipated amount represents the unpaid amount of principal and interest, and may include reasonable compensation for cancellation anticipated of the contract regardless of the event that causes the anticipated termination. These amendments are effective for annual periods beginning on or after January 1, 2019. As they are accounting practices of the Company, no effect is expected on its financial statements. Amendments to IAS 1 and IAS 8 regarding the definition of materiality In October 2018 the IASB included certain amendments to IAS 1 “Presentation of financial statements” and IAS 8 “Accounting policies, changes in accounting estimates and errors” with the objective of clarifying the concept of materiality and aligning that definition with the amendments introduced in the Conceptual Framework. Additionally, these amendments incorporate new concepts that helped both financial statement preparers and their users to prepare and interpret the financial information included in them. These amendments are applied on prospective basis and are effective for annual periods beginning on or after January 1, 2020. Early adoption is permitted. b) Consolidation Subsidiary Subsidiaries are all entities over which the Company has control. The Company controls an entity when the Company is exposed to, or has rights to, variable returns from its involvement and has the ability to affect those returns through its power over the entity. Subsidiaries are fully consolidated from the date on which control is transferred to the group. They are deconsolidated from the date that control ceases. For this purpose and unless there are specific requirements, it is generally considered that TGS has control, when it has a participation equal to or greater than 50% of the available voting rights. The accounting policies of the subsidiaries are consistent with the accounting policies adopted by the Company. Inter-company transactions, balances and gain/losses from transactions between group companies are eliminated. Unrealized gain/losses are also eliminated. Detailed data reflecting subsidiary control as of December 31, 2018 and 2017 is as follows: % of shareholding Company and votes Country Closing date Main activity TGU 99.98 Argentina December 31 Telecommunication Services CTG (1) 100.00 Argentina December 31 Electricity related services (1) 100% of the shares of this company were acquired on August 8, 2017. At present, it is in the process of being transformed into S.A.U. For consolidation purposes for the year ended December 31, 2018 and 2017, the financial statements of Telcosur have been used at those dates. The subsidiary CTG does not record operations or significant assets and liabilities as of December 31, 2018 and 2017. Associates Associates are entities over which the group has significant influence but not control, generally accompanying a shareholding of between 20% and 50% of the voting rights. Investments in associates are accounted for using the equity method of accounting. Under the equity method, the investment is initially recognized at cost, and the carrying amount is increased or decreased to recognize the investor’s share of the profit or loss of the investee after the date of acquisition. The Company accounted for the investments in its associates, under the equity method on the basis on the financial statements as of September 30, 2018 of Gas Link S.A Transporte y Servicios de Gas en Uruguay SA Emprendimientos de Gas del Sur S.A. Associates with negative equity are disclosed under “Other liabilities” to the extent that the Company has incurred legal or constructive obligations, or made payments on behalf of the associate, as of the date of the financial statements. Unrealized gains and losses resulting from transactions between TGS and the associate or joint venture are eliminated to the extent of the interest in the associate or joint venture. In the table below, associates are disclosed, together with the percentage of shareholding and voting as of December 31, 2018 and 2017: % of Shareholding Company and voting Country Main activity Closing date TGU 49.00 Uruguay Pipeline maintenance December 31 EGS (“in liquidation”) 49.00 Argentina Pipeline exploitation and construction December 31 Link 49.00 Argentina Pipeline exploitation and construction December 31 Joint arrangement As indicated in “Note 23 – Associates and Joint Arrangement”, on August 7, 2017, the Company proceeded to create a UT (similar to a joint operation) with SACDE Sociedad Argentina de Construcción y Desarrollo Estratégico S.A. The Company has defined that the UT constitutes a joint operation given that it grants its participants a percentage of the rights over the assets and liabilities arising from each contract. Accordingly, the Company recognizes its share in the jointly operated assets, liabilities, revenues, costs and expenses. Accounting policies applicable to the UT have been modified and adapted, if applicable, to ensure consistency with the policies adopted by the Company. For further information regarding the UT, see Note 23. c) Foreign currency translation Functional and presentation currency The consolidated financial statements are presented in thousands of Argentine Pesos, which is the Company’s functional currency. Each subsidiary or associate determines its own functional currency based on the currency of the primary economic environment in which these entities operate. Transactions and balances Foreign currency transactions are translated into the functional currency using the exchange rates prevailing at the dates of the transactions or valuation where items are remeasured. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at year-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized in the profit or loss for the year. Foreign exchange gains and losses are presented in the statement of comprehensive income within financial income and financial expenses, as appropriate. Associates The functional currency of the associate company located abroad, TGU, is the US dollar, because it is the currency in which it substantially generates its income and incur its expenses. Assets and liabilities were converted into Argentine pesos using the exchange rate prevailing at the end of each year, their common stock and retained earnings at their historical exchange rates and results at average exchange rates. d) Restatement to constant currency - Comparative Information Regulatory framework The consolidated financial statements as of December 31, 2018, including comparative figures, have been restated to take into account changes in the general purchasing power of the Company’s functional currency (the Argentine peso) in accordance with IAS 29 “Financial Reporting in hyperinflationary economies “(“IAS 29”) and CNV General Resolution No. 777/2018. As a result, the financial statements are stated in terms of the current unit of measurement at the 2018 balance sheet date. IAS 29 requires that the financial statements of an entity that reports in the currency of a hyperinflationary economy, regardless of whether they are based on the historical cost method or the current cost method, are expressed in terms of the current unit of measurement at the closing date of the reporting period. In order to conclude on the existence of a hyperinflationary economy, the standard details a series of factors to be considered, among which is a cumulative inflation rate over three years that approaches or exceeds 100%. During the year 2017, the cumulative inflation rate over three years remained in Argentina in decreasing values ​​with respect to 2016 and below the accumulated 100% in three years. However, this trend has reversed during the first half of 2018 due to factors such as the devaluation of the exchange rate with its effect on the price of imported inputs, the continuity of the process of adjusting public service tariffs, as well as an unfavorable international context in financial issues. In this scenario, accumulated three-year inflation, measured both on the basis of wholesale price indexes and consumer price indexes, is currently above 100%, and the available projections indicate that this trend will not be reversed in the short-term. In order to evaluate the aforementioned quantitative condition, and also to restate the financial statements, the CNV has established that the series of indexes to be used for the application of IAS 29 is determined by the FACPCE. This series of indexes combines the National Consumer Price Index (“CPI”) as of January 2017 (base month: December 2016) with the Domestic Wholesale Price Index (“WPI”), both published by the Institute National Statistics and Census (“INDEC”) until that date. For the months of November and December 2015, for which there is no information from the INDEC on the evolution of the WPI, the variation in the CPI of the Autonomous City of Buenos Aires was applied. Considering the aforementioned index, inflation was 47.64%, 24.79% and 34.59% in the years ended December 31, 2018, 2017 and 2016 respectively. Restatement mechanism The financial statements must be adjusted to consider changes in the general purchasing power of the currency, so that they are expressed in the current unit of measurement at the end of the reporting period. Said requirements also include all the comparative information of the financial statements, without modifying the decisions made based on the financial information corresponding to those financial years. Restatement of the balance sheet i. Monetary items (those with a fixed nominal value in local currency) are not restated, since they are already expressed in the current unit of measurement at the closing date of the reporting period. In an inflationary period, maintaining monetary assets generates loss of purchasing power and maintaining monetary liabilities generates a gain in purchasing power, provided that such items are not subject to an adjustment mechanism that compensates to some extent for these effects. The monetary loss or gain is included in the result of the period in which it is reported. ii. The non-monetary items measured at their current values ​​at the end of the reporting period are not restated for the purpose of their presentation in the balance sheet, but the adjustment process must be completed to determine in terms of a homogeneous unit of measurement the results produced by the holding of these non-monetary items. iii. Non-monetary items measured at historical cost or at a fair value as of a date prior to the closing date of the reporting period are restated by coefficients that reflect the variation in the general price level from the date of acquisition or revaluation to the closing date, proceeding then to compare the restated amounts of those assets with the corresponding recoverable values. iv. The restatement of non-monetary assets in the terms of the current unit of measurement at the end of the reporting period without an equivalent adjustment for tax purposes, results in a temporary taxable difference and the recognition of a deferred tax liability whose counterparty is recognized in the result of the period. For the closing of the subsequent period, the deferred tax items are restated for inflation to re-determine the charge to the result of the next period. v. When the capitalization of costs for loans in non-monetary assets in accordance with IAS 23 is applicable, the portion of those costs that compensate the lender for the effects of inflation is not capitalized. For the years ended December 31, 2018 and 2017 the Company did not capitalize financial costs. Restatement of the Comprehensive Income Statement Revenues and expenses (including interest and foreign exchange differences) are restated from the date of their booking, except for those items of the result that reflect or include in their determination the consumption of assets measured in purchasing power of a date before the consumption booked, which are restated based on the date of origin of the asset to which the item is related (for example, depreciation and other consumption of assets valued at historical cost); and also those results that arise from comparing two measurements expressed in purchasing power currency of different dates, for which it is necessary to identify the amounts compared, restate them separately, and make the comparison, but with the amounts already restated. The result of the exposure to the change in the purchasing power of the currency (monetary results) is presented in a separate line and reflects the effect of inflation on the monetary items. Restatement of the statement of changes in equity As of the transition date (January 1, 2016), the Company applied the following special rules: i. The components of the capital stock were restated from the dates they were contributed. ii. Reserved earnings were maintained at the date of transition at their nominal value (legal amount without restatement). iii. The restated unallocated results were determined by the difference between the net assets restated at the transition date and the rest of the initial equity components expressed as indicated in the preceding sections. iv. After the restatement at the transition date, all the components of the equity are restated by applying the general price index from the beginning of the period, and each variation of those components is restated from the date of contribution or from the moment in which is added by any other means. Restatement of the statement of cash flows IAS 29 requires that all items in this statement should be restated in terms of the current unit of measurement as of the closing date of the period for which it is reported. The monetary result generated by cash and cash equivalents is presented in the statement of cash flows separately from cash flows from operating, investing and financing activities, as a specific item of the reconciliation between cash and cash equivalents at the beginning and at the end of the year. The effects of adopting IAS 29 on equity at the transition date and as of December 31, 2017 and 2018 and the results for the year 2016 and 2017 are as follows: Balances as of 01/01/2016 Balances as of 12/31/2016 Balances as of 12/31/2017 Total equity according to financial statements approved on 04/13/2018 1,695,434 2,526,378 5,319,640 Increase due to adjustment of common stock 17,321,734 17,321,734 17,321,734 (Decrease) / increase in accumulated retained earnings (368,161 ) (319,709 ) 2,638,215 Total equity after the application of IAS 29 18,649,007 19,528,403 25,279,589 2016 2017 Total comprehensive income for the year ended December 31, 2016 and 2017 according to financial statements approved on 04/13/2018 930,678 2,793,266 Gain on net monetary position 1,038,647 465,975 Restatement of income / (expense) items including income tax (863,030 ) 2,491,952 Total comprehensive income after the application of IAS 29 1,106,295 5,751,193 e) Financial instruments Financial assets Recognition and initial measurement As of January 1, 2018, financial assets are classified, at the time of initial recognition, as: i. Financial assets subsequently measured at amortized cost, and ii. Financial assets subsequently measured at fair value (either with changes in other comprehensive income or with changes in results). The classification of financial assets at initial recognition depends on the financial asset’s contractual cash flow characteristics and the Company’s business model for managing them. For additional information, see Note 16.2.1. Financial assets are initially measured at fair value, net of transaction costs except for those financial assets classified at fair value through profit or loss. Financial assets at fair value through profit or loss are initially recognized at their fair value while transaction costs are expensed. Subsequent measurement After initial recognition, financial assets are measured according to their initial classification according to the following categories: Financial assets at amortized cost It is the most relevant category used by the Company, financial assets are classified and measure at amortized cost if both of the following conditions are met: • The financial asset is held within a business model with the objective to hold financial assets in order to collect contractual cash flows; and • The contractual terms of the financial asset give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. Financial assets at amortized cost are subsequently measured using the effective interest method. Gains and losses are recognized in the Statement of Comprehensive Income under financial results when the asset is derecognized, modified or impaired. Financial assets at fair value through OCI (Debt instruments) Corresponds to financial assets that are maintained in a business model whose objective is achieved by obtaining contractual cash flows and selling them. Unrealized gains or losses arising from changes in fair value are recognized as other comprehensive income, except for the accrual of interest, exchange rate difference and the impairment of such assets that are recognized as financial results in the Statement of Comprehensive Income. At the time the asset is written off, the accumulated gain or loss is recognized as a financial result and it is eliminated from the respective reserve. Financial assets designated at fair value through OCI (equity instruments) Upon initial recognition, the Company can elect to classify irrevocably its equity investments as equity instruments designated at fair value through OCI when they meet the definition of equity under IAS 32. Gains and losses on these financial assets are never recycled to profit or loss. Dividends are recognized as other income in the Statement of Comprehensive Income when the right of payment has been established, except when the Company benefits from such proceeds as a recovery of part of the cost of the financial asset, in which case, such gains are recorded in OCI. Equity instruments designated at fair value through OCI are not subject to impairment assessment. Financial assets at fair value through profit or loss In the event that financial assets are not classified according to the aforementioned categories, they will be subsequently measured at fair value, presenting gains or losses arising from changes in fair value in the income statement within financial results in the year in which they are originated. Impairment of financial assets The Company applies the PE model for those financial assets accounted for at amortized cost or at fair value through OCI. The PE is based on the difference between the contractual cash flows due in accordance with the contract and the cash flows that the Company expects to receive, discounted at an approximation of the original effective interest rate. To this end, the Company evaluates various factors, including credit risk, historical trends and other available information. The application of this model implies recognition of: • Expected credit losses within of 12 months: these are expected credit losses that result from possible default events within 12 months after the filing date; and • Expected credit losses during the life of the asset: these are expected credit losses that result from possible events of default during the e

CRITICAL ACCOUNTING ESTIMATES A

CRITICAL ACCOUNTING ESTIMATES AND JUDGMENTS	12 Months Ended
	Dec. 31, 2018
CRITICAL ACCOUNTING ESTIMATES AND JUDGMENTS [Abstract]
CRITICAL ACCOUNTING ESTIMATES AND JUDGMENTS	5. CRITICAL ACCOUNTING ESTIMATES AND JUDGMENTS The preparation of the financial statements in accordance with professional accounting standards requires the Company to make accounting estimates that affect the amounts of assets and liabilities recorded and the disclosure of contingent assets and liabilities as of the date of the financial statements, as well as the amounts of income and expenses recorded during the corresponding period. (a) Provisions for legal claims and others The Company has certain liabilities with respect to existing court or out-of-court claims, lawsuits and other proceedings, including those involving legal and regulatory matters. The Company records liabilities when it is probable that future costs will be incurred and such costs can be reasonably estimated. Such provisions are based on developments known at the date of the issuance of these consolidated financial statements, estimates of the outcome of these matters and the experience of its legal counsel in contesting, litigating and settling other matters. As the scope of the liabilities become better defined, there will be changes in the estimates of future costs, which could have a material effect on the Company’s future results of operations and financial condition or liquidity. (b) Income Tax Deferred tax assets are recognized for all tax losses to the extent that it is probable that there will be a tax benefit against which these losses can be utilized. Determining the amount of deferred tax assets that can be booked requires a considerable judgment by our management, based on the probable term and level of future taxable profits together with future tax planning strategies and macroeconomic variables affecting the business. On December 29, 2017, the PEN promulgated and put into effect through Decree 1112/2017 a tax reform enacted in the Argentine National Congress through Law No. 27,430 (the “Tax Reform”). Among other issues, this reform establishes a gradual reduction of the applicable rate for the calculation of income tax, being 35%, 30% and 25% for fiscal periods 2017, 2018/19 and 2020 onwards, respectively. Note 14 “Income tax and deferred tax” includes more detailed information on Income Tax. (c) Impairment of PPE As mentioned in Note 4.j, the Company periodically evaluates the existence of events or significant changes that could have adverse effects on the Company or will take place in the near future that could affect the recoverable value of the PPE amounts. These evaluations are carried out at the lowest level for which there are identifiable cash flows, that is, for each single cash CGU. TGS considers each of its business segments to be a CGU. Some of the indications that the Company evaluates to determine the existence of trigger events that could lead to the impairment of PPE value are the following, among others: • Whether significant decreases in the market values of PPE elements took place. • Whether prices of the main products and services that are marketed decreased. • Whether significant changes in the regulatory framework were introduced. • Whether operating costs suffered a materially increase. • Whether evidence of obsolescence or physical damage has occurred. • Whether the macroeconomic situation in which TGS carries out ou activities, including significant variations in the sale prices of products, raw materials, interest rates, etc, has worsen. The value in use is calculated on the basis of discounted future cash flows. The projected cash flows are prepared taking into account: (i) for assets associated with the Liquids and Commercialization segment, projections of the prices of liquids and purchase cost of natural gas used as raw material (ii) for assets associated with the Natural Gas Transportation segment, estimates of future tariff adjustments and the recognition of cost adjustments (iii) projections of the future costs to be incurred, (iv) expected macroeconomic variables such as interest rates, inflation, foreign exchange rates. The discount rate is based on a weighted average cost of capital (“WACC”). No impairment indicators were identified as of December 31, 2018 and 2017.

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	12 Months Ended
	Dec. 31, 2018
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	6. SUPPLEMENTAL CASH FLOW INFORMATION For purposes of the consolidated statement of cash flows, the Company considers all highly liquid temporary investments with an original maturity of three months or less at the time of purchase to be cash equivalents. The cash flow statement has been prepared using the indirect method, which requires a series of adjustments to reconcile net income for the period to net cash flows from operating activities. Non-cash investing and financing activities for the years ended December 31, 2018, 2017 and 2016 are presented below: 2018 2017 2016 Unpaid acquisition of PPE 307,746 299,598 47,198 Principal payment of financial lease (1) 101,965 66,075 271,843 Leasing for PPE acquisition - 1,429,713 (1) Cancelled through compensation with trade receivables with the creditor. See Note 13. Note 13 to these consolidated financial statements includes a reconciliation between the initial and final balance of the financial liabilities arising from financing activities.

CONSOLIDATED BUSINESS SEGMENT I

CONSOLIDATED BUSINESS SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2018
CONSOLIDATED BUSINESS SEGMENT INFORMATION [Abstract]
CONSOLIDATED BUSINESS SEGMENT INFORMATION	7. CONSOLIDATED BUSINESS SEGMENT INFORMATION IFRS 8 “Operating Segments” requires an entity to report financial and descriptive information about its reportable segments, which are operating segments or aggregations of operating segments that meet specified criteria. Operating segments are components of an entity about which separate financial information is available that is evaluated regularly by the CODM in deciding how to allocate resources and in assessing performance. The Company’s CODM is the Board of Directors. Operating segments identified are disclosed as reportable segments if they meet any of the following quantitative thresholds: • Reported revenues of the operating segments are 10% or more of the combined revenue, internal and external, of all operating segments; • The absolute amount of reported profit or loss is 10% or more of the greater, in absolute amount, of (i) the combined reported profit of all operating segments that did not report a loss and (ii) the combined reported loss of all operating segments that reported a loss. • Assets are 10% or more of the combined assets of all operating segments As well as this, the operating segments that do not meet any of the quantitative thresholds can be considered as reportable segments if the management estimates that this information could be useful for the users of the financial statements. If, after determining reportable segments in accordance with the preceding quantitative thresholds, the total external revenue attributable to those segments amounts to less than 75% of the total Company’s consolidated external revenue, additional segments are identified as reportable segments, even if they do not meet the thresholds described above, until at least 75% of the Company’s consolidated external revenue is included in reportable segments. Segment information has been prepared and classified according to different types of businesses in which the Company conducts its activities. The four reportable segments are: (i) Natural Gas Transportation; (ii) Production and Commercialization of Liquids; (iii) Other services and (iv) Telecommunications. For more information regarding the services provided in each of the business segments, see Note 4.p. Detailed information on each business segment for the years ended December 31, 2018, 2017 and 2016 is disclosed below: Year ended December 31, 2018 Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Eliminations Total Revenues 15,462,061 16,627,429 1,810,109 163,071 - 34,062,670 Intercompany revenues 598,414 - - - (598,414 ) - Cost of sales (5,164,278 ) (10,485,998 ) (1,054,245 ) (82,203 ) 598,414 (16,188,310 ) Administrative expenses (835,134 ) (84,062 ) (35,980 ) (6,637 ) - (961,813 ) Selling expenses (953,729 ) (640,173 ) (143,451 ) (27,348 ) - (1,764,701 ) Other operating expenses (156,283 ) (726,732 ) (5,445 ) (2,327 ) - (890,787 ) Operating profit 8,951,051 4,690,464 570,988 44,556 - 14,257,059 Depreciation of property, plant and equipment (1,880,377 ) (113,737 ) (228,969 ) - - (2,223,083 ) Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Total Identifiable assets 45,246,427 9,040,987 7,554,646 100,967 61,943,027 Identifiable Liabilities 16,738,045 1,496,225 12,717,432 46,020 30,997,722 Year ended December 31, 2017 Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Eliminations Total Revenues 7,456,052 11,173,975 1,199,170 124,069 - 19,953,266 Intercompany revenues 245,161 - - - (245,161 ) - Cost of sales (4,178,865 ) (7,271,556 ) (655,830 ) (74,592 ) 245,161 (11,935,682 ) Administrative expenses (597,122 ) (93,720 ) (36,475 ) (6,557 ) - (733,874 ) Selling expenses (419,570 ) (265,336 ) (106,916 ) (15,474 ) - (807,296 ) Other operating expenses (327,245 ) 64,694 (9,198 ) 154 - (271,595 ) Operating profit 2,178,411 3,608,057 390,751 27,600 - 6,204,819 Depreciation of property, plant and equipment (1,695,112 ) (95,318 ) (229,786 ) - - (2,020,216 ) Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Total Identifiable assets 34,792,004 6,846,690 3,069,476 145,257 44,853,427 Identifiable Liabilities 15,451,091 2,176,705 1,907,129 38,913 19,573,838 Year ended December 31, 2016 Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Eliminations Total Revenues 4,162,220 9,404,793 956,948 121,549 - 14,645,510 Intercompany revenues 138,502 - - - (138,502 ) - Cost of sales (3,259,674 ) (6,407,872 ) (433,877 ) (62,503 ) 138,502 (10,025,424 ) Administrative expenses (784,885 ) (61,573 ) (27,850 ) (6,459 ) - (880,767 ) Selling expenses (239,294 ) (353,913 ) (87,741 ) (14,910 ) - (695,858 ) Other operating expenses (90,032 ) (37,417 ) (2,350 ) (845 ) - (130,644 ) Operating profit (73,163 ) 2,544,018 405,130 36,832 - 2,912,817 Depreciation of property, plant and equipment (1,884,543 ) (87,926 ) (122,949 ) - - (2,095,418 )

DETAIL OF SIGNIFICANT STATEMENT

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS	12 Months Ended
	Dec. 31, 2018
DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS [Abstract]
DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS	8. DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS a) Other receivables 2018 2017 Current Non Current Current Non Current VAT credit balance 300,272 - 155,570 - Other tax receivables 9,988 2,044 10,674 3,786 Prepaid expenses 47,756 - 32,162 - Advances to suppliers 1,850,997 - 554,417 - Subsidies receivables 292,866 - 255,886 - Guaranteed deposits 1,139 - - - Other Receivables UT 29,706 - 3,318 - Others 130,334 6,189 14,576 14,088 Total 2,663,058 8,233 1,026,603 17,874 b) Trade receivables 2018 2017 Current Non Current Current Non Current Commons 2,898,908 - 2,965,995 4,511 UT 20,442 - 225,565 - Natural Gas Transportation 1,657,456 - 1,314,592 - Production and Commercialization of Liquids 1,092,536 - 1,342,194 - Other services 128,474 - 83,644 4,511 Related parties (Note 21) 348,112 - 36,437 - Natural Gas Transportation 73,243 - 14,302 - Production and Commercialization of Liquids 8,124 - - - Other services 266,745 - 22,135 - Allowance for doubtful accounts (132,521 ) - - - Total 3,114,499 - 3,002,432 4,511 The movement of the allowance for doubtful accounts is as follows: For doubtful accounts Balances as of 12/31/2016 36,304 Inflation adjustment restatement (12,909 ) Additions - Applications - Decreases (1) (23,395 ) Balances as of 12/31/2017 - Additions (1) 132,521 Applications - Decreases - Balances as of 12/31/2018 132,521 (1) The total amount is recorded in Selling Expenses c) Cash and cash equivalents 2018 2017 Cash and banks 5,964,008 981,710 UT Cash and banks 153 695 Mutual funds 610,108 - Bank account 2,146,801 1,866,194 Interest-bearing accounts 7,909,391 973,646 UT Mutual funds 14,366 94,502 Total 16,644,827 3,916,747 d) Contract liabilities 12/31/2018 1/1/2018 Current Non Current Current Non Current Natural Gas Transportation 67,978 1,198,855 101,990 1,257,599 Production and Commercialization of Liquids 25,514 255,075 14,546 269,614 Other services 2,018 15,121 11,888 7,927 UT 34,068 - 88,396 - Total 129,578 1,469,051 216,820 1,535,140 During fiscal year 2018, the Company recognized Ps. 118,820 in revenues from sales from contract with customers in the Statement of Comprehensive Income, which had been included in the balance at the beginning of the year. e) Advances from customers 2018 2017 Current Non Current Current Non Current Natural Gas Transportation - - 101,990 1,257,599 Production and Commercialization of Liquids - - 14,546 269,614 Other Services - - 11,888 7,927 UT - - 88,396 - Total - - 216,820 1,535,140 f) Other payables 2018 2017 Current Non Current Current Non Current UT Other liabilities 73,621 - - - Provision for compensation for the Board of Directors and Supervisory Committee Supervisory Commitee 5,409 - - - Justice fee payable - - 47,072 - Others 1,644 - 2,459 - Total 80,674 - 49,531 - g) Taxes payables 2018 2017 Current Non Current Current Non Current Withholdings for income tax made to third parties 110,623 - 79,749 - Health and safety tax 8,790 - - - Turnover Tax 62,714 - 42,613 - UT Others 2,752 - - - Others 17,343 - 20,200 - Total 202,222 - 142,562 - h) Trade payables 2018 2017 Current Non Current Current Non Current Suppliers 2,798,453 - 1,967,080 - UT Suppliers 90,252 - 11,236 - Customers (credit balances) 2,235 - 15,851 - Related parties (Note 21) 201,097 - 151,571 - Total 3,092,037 - 2,145,738 - i) Revenues 2018 2017 2016 Sales of goods and services 33,655,943 19,605,611 14,331,482 Subsidies 406,727 347,655 314,028 Total 34,062,670 19,953,266 14,645,510 Disaggregation of revenues Below is a table in which revenues are disaggregated considering the type of market and the opportunity to satisfy performance obligations: Year ended December 31, 2018 Natural gas transportation Production and commercialization of liquids Other services Telecommunications Total Primary geographical market: External market - 6,025,445 - - 6,025,445 Domestic market 15,462,061 10,601,984 1,810,109 163,071 28,037,225 Total 15,462,061 16,627,429 1,810,109 163,071 34,062,670 Timing of revenue recognition: Over the time 15,462,061 705,309 1,810,109 163,071 18,140,550 At a point in time - 15,922,120 - - 15,922,120 Total 15,462,061 16,627,429 1,810,109 163,071 34,062,670 Year ended December 31, 2017 Natural gas transportation Production and commercialization of liquids Other services Telecommunications Total Primary geographical market: External market - 4,332,548 - - 4,332,548 Domestic market 7,456,052 6,841,427 1,199,170 124,069 15,620,718 Total 7,456,052 11,173,975 1,199,170 124,069 19,953,266 Timing of revenue recognition: Over the time 7,456,052 534,842 1,199,170 124,069 9,314,133 At a point in time - 10,639,133 - - 10,639,133 Total 7,456,052 11,173,975 1,199,170 124,069 19,953,266 Year ended December 31, 2016 Natural gas transportation Production and commercialization of liquids Other services Telecommunications Total Primary geographical market: External market - 2,841,403 - - 2,841,403 Domestic market 4,162,220 6,563,390 956,948 121,549 11,804,107 Total 4,162,220 9,404,793 956,948 121,549 14,645,510 Timing of revenue recognition: Over the time 4,162,220 570,904 956,948 121,549 5,811,621 At a point in time - 8,833,889 - - 8,833,889 Total 4,162,220 9,404,793 956,948 121,549 14,645,510 Detailed information of revenues on each business segment for the years ended December 31, 2018, 2017 and 2016 is disclosed below: i. Natural Gas Transportation: 2018 2017 2016 Firm 12,243,699 5,831,927 2,988,232 Access and Charge 565,809 433,575 420,897 Interruptible and Others 2,652,553 1,190,550 753,091 Total 15,462,061 7,456,052 4,162,220 ii. Production and Commercialization of Liquids: 2018 2017 2016 Product 15,515,393 10,255,416 8,062,864 Services 705,309 570,904 1,027,901 Government grants 406,727 347,655 314,028 Total 16,627,429 11,173,975 9,404,793 iii. Other services: 2018 2017 2016 Conditioning and treatment 735,099 546,758 410,644 Operation and maintenance 480,112 414,576 328,975 Steam sales 136,764 96,587 106,212 Construction 21,321 138,638 100,543 UT Construction 433,200 - - Others 3,613 2,611 10,574 Total 1,810,109 1,199,170 956,948 j) Cost of sales 2018 2017 2016 Inventories at the beginning of the year 183,745 241,477 240,933 Purchases 8,860,447 6,013,669 5,453,359 Operating costs (Note 8.k.) 7,504,392 5,864,281 4,572,609 Inventories at the end of the year (360,274 ) (183,745 ) (241,477 ) Total 16,188,310 11,935,682 10,025,424 k) Expenses by nature – Information required under art. 64 paragraph I, clause B) Commercial Companies Law 2018 Operating expenses Accounts Total Regulated Activities Non Regulated Administrative expenses Selling expenses Financial expenses Salaries, wages and other compensations 1,912,950 891,140 567,798 356,913 97,099 - Social security taxes 320,232 144,748 84,940 69,616 20,928 - Compensation to Directors and Supervisory Committee 25,819 - - 25,819 - - Professional services fees 274,697 7,047 135,626 125,232 6,792 - Technical operator assistance fees 1,317,176 838,032 479,144 - - - Materials 223,940 68,688 155,252 - - - Third parties services 261,779 102,315 130,258 19,790 9,416 - Telecommunications and post expenses 21,776 4,196 2,857 14,258 465 - Rents 24,786 7,657 10,301 5,946 882 - Transports and freight 68,094 42,231 22,984 2,879 - - Easements 54,076 54,076 - - - - Offices supplies 6,997 2,371 861 3,130 635 - Travels expenses 85,273 38,173 26,740 16,396 3,964 - Insurance 66,269 38,167 23,695 4,404 3 - Property, plant and equipment maintenance 1,265,254 1,105,531 144,116 15,607 - - Depreciation of property, plant and equipment 2,223,083 1,612,884 342,706 267,493 - - Taxes and contributions 1,675,901 170,521 20,082 2,128 1,483,170 (1) - Advertising 4,856 - - - 4,856 - Doubtful accounts 132,521 - - - 132,521 - Banks expenses 12,150 - - 12,150 - - Interests expense 1,675,437 - - - - 1,675,437 Foreign exchange loss 13,122,031 - - - - 13,122,031 Other financial charges 243,524 - - - - 243,524 Costs of services rendered to third parties 165,277 - 165,277 - - - Other expenses 88,000 36,501 27,477 20,052 3,970 - Total 2018 25,271,898 5,164,278 2,340,114 961,813 1,764,701 15,040,992 (1) Includes tax on exports for Ps. 248,883 2017 Operating expenses Accounts Total Regulated Activities Non Regulated Activities Administrative expenses Selling expenses Financial expenses Salaries, wages and other compensations 1,791,444 864,168 469,199 357,902 100,175 - Social security taxes 308,469 135,826 80,500 70,258 21,885 Compensation to Directors and Supervisory Committee 13,816 - - 13,816 - - Professional services fees 99,599 2,409 4,931 83,979 8,280 - Technical operator assistance fees 577,187 260,036 317,151 - - - Materials 97,057 29,979 67,078 - - - Third parties services 206,456 85,959 103,408 17,089 - - Telecommunications and post expenses 16,093 2,150 1,972 11,196 775 - Rents 10,939 3,161 1,581 5,442 755 - Transports and freight 57,869 34,450 19,772 3,614 33 - Easements 35,265 35,265 - - - - Offices supplies 5,612 1,665 585 2,618 744 - Travels expenses 31,035 13,879 5,113 8,991 3,052 - Insurance 52,660 30,744 17,527 3,909 480 - Property, plant and equipment maintenance 1,005,258 865,572 129,280 8,639 1,767 - Depreciation of property, plant and equipment 2,020,216 1,569,839 325,104 125,273 - - Taxes and contributions 918,821 213,123 13,395 1,186 691,117 (1) - Advertising 767 - 3 - 764 - Doubtful accounts (23,395 ) - - - (23,395 ) - Banks expenses 7,217 - - 7,217 - - Interests expense 846,366 - - - - 846,366 Foreign exchange loss 1,117,201 - - - - 1,117,201 Other financial charges 167,920 - - - - 167,920 Costs of services rendered to third parties 115,272 - 115,272 - - - Other expenses 57,794 30,640 13,545 12,745 864 - Total 2017 9,536,938 4,178,865 1,685,416 733,874 807,296 2,131,487 (1) Includes tax on exports for Ps. 1,286 2016 Operating expenses Accounts Total Regulated Activities Non Regulated Activities Administrative expenses Selling expenses Financial expenses Salaries, wages and other contributions 1,603,431 796,925 393,027 321,349 92,130 - Social security taxes 276,390 128,245 66,702 61,543 19,900 - Compensation to Directors and Supervisory Committee 12,345 - - 12,345 - - Professional services fees 80,706 2,580 7,002 64,122 7,002 - Technical operator assistance fees 329,826 105,950 223,876 - - - Materials 85,497 28,376 57,121 - - - Third parties services 183,154 72,598 95,078 15,478 - - Telecommunications and post expenses 9,766 553 2,211 6,818 184 - Rents 6,818 1,658 737 4,054 369 - Transports and freight 54,541 33,904 19,347 1,290 - - Easements 38,326 38,326 - - - - Offices supplies 5,159 1,843 737 2,395 184 - Travels expenses 19,533 9,582 2,764 5,344 1,843 - Insurance 51,962 29,666 18,242 3,501 553 - Property, plant and equipment maintenance 408,504 294,447 102,080 9,766 2,211 - Depreciation of property, plant and equipment 2,095,419 1,527,999 210,876 356,544 - - Taxes and contributions 703,136 160,122 17,320 1,474 524,220 (1) - Advertising 737 - - - 737 - Doubtful accounts 38,142 - - - 38,142 - Banks expenses 4,054 - - 4,054 - - Interests expense 937,454 - - - - 937,454 Foreign exchange loss 1,486,399 - - - - 1,486,399 Other financial charges 131,536 - - - - 131,536 Derivate financial instruments 9,383 - - - - 9,383 Costs of services rendered to third parties 84,207 - 84,207 - - - Other expenses 57,581 26,900 11,608 10,690 8,383 - Year ended Deccember 31, 2016 8,714,006 3,259,674 1,312,935 880,767 695,858 2,564,772 (1) Includes tax on exports of Ps. 11,081 for the year ended December 31, 2016. l) Net financial results 2018 2017 2016 Financial income Derivative financial instrument results 106,084 - - Interest income 1,345,278 133,116 206,402 Fair value gains on financial instruments through profit or loss 1,372,933 442,480 329,401 Foreign exchange gain 8,164,243 561,572 280,988 Subtotal 10,988,538 1,137,168 816,791 Financial expenses Interest expense (1,675,437 ) (846,366 ) (937,454 ) Foreign exchange loss (13,122,031 ) (1,117,201 ) (1,486,399 ) Derivative financial instrument results - - (9,383 ) Other financial charges (243,524 ) (167,920 ) (131,536 ) Less: C - - - Subtotal (15,040,992 ) (2,131,487 ) (2,564,772 ) Gain on net monetary results 1,206,195 465,975 1,038,647 Total (2,846,259 ) (528,344 ) (709,334 ) In accordance with the provisions of IAS 29, the Company opted to present the gain on the monetary position in a single line included in the financial results. This exposure implies that the nominal magnitudes of the financial results have been adjusted for inflation. The real magnitudes of financial results are different from the components of financial results presented above. For additional information see Note 4.d., to these consolidated financial statements. m) Other operating expenses 2018 2017 2016 Disposal of property, plant and equipment (158,516 ) (131,419 ) (16,368 ) Net increase in provisions (1) (770,802 ) (228,196 ) (124,437 ) Recovery of insurance 23,874 194,689 - Write off of other receivables - (105,047 ) - Others 14,657 (1,622 ) 10,161 Total (890,787 ) (271,595 ) (130,644 ) (1) Includes judicial costs n) Other financial assets at fair value through profit or loss 2018 2017 Current Non Current Current Non Current Government bonds - - 218,707 - Private bonds - - 106,451 - Total - - 325,158 - o) Other financial assets at amortized cost 2018 2017 Current Non Current Current Non Current VRD bonds 5,714 8,760 10,499 21,369 Government Bonds (Argentine National Treasury Notes) - - 1,361,756 - Government Bonds (Central Bank Notes) - - 761,856 - Total 5,714 8,760 2,134,111 21,369 p) Payroll and social security taxes payable 2018 2017 Current Non Current Current Non Current Vacation benefit payable 170,690 - 154,643 - Annual bonus payable 133,365 - 125,344 - Social security taxes payable 67,381 - 67,287 - UT 12,200 - - - Total 383,636 - 347,274 -

INVESTMENTS IN ASSOCIATES

INVESTMENTS IN ASSOCIATES	12 Months Ended
	Dec. 31, 2018
INVESTMENTS IN ASSOCIATES [Abstract]
INVESTMENTS IN ASSOCIATES	9. INVESTMENTS IN ASSOCIATES 2018 2017 Issuer Information Description of securities Last financial statemets issued Name and issuer Face value Amount Cost Book value Main business Date Common stock Net (loss) / income for the year / period Shareholders’ equity % of Common Stock Book value Transporte y Servicios de Ps. Uru. 1 196,000 118 5,798 Pipeline maintenance 09/30/2018 28 (689 ) 11,832 49.00 3,981 Emprendimientos de Gas del Sur S.A. (in liquidation) $ 1 116,130 116 324 Pipeline construction and operation services 09/30/2018 237 (70 ) 661 49.00 543 Gas Link S.A. $ 1 502,962 5,587 66,548 Pipeline construction and operation services 09/30/2018 1,026 30,918 145,949 49.00 51,400 Total 72,670 55,924

JOINT ARRANGEMENTS

JOINT ARRANGEMENTS	12 Months Ended
	Dec. 31, 2018
JOINT ARRANGEMENTS [Abstract]
JOINT ARRANGEMENTS	10. JOINT ARRANGEMENTS TGS jointly with SACDE applied for the public tender launched by the Argentine Government for the construction of a connection pipeline in the province of Santa Fe. This tender was finally obtained by the UT whose sole purpose is the execution of such works that would extend until March 31, 2019. For further information, see Note 23. The Company participates in the UT in a percentage of 51% on the rights of the assets and on the obligations related to them. TGS consolidates line by line assets, liabilities and results of the UT based on the aforementioned percentage of participation. The breakdown of the amounts included in the statements of financial position related to the Company’s participation in the UT and as of December 31, 2018 and 2017 and for the three years ended December 31, 2018 is the following: 2018 2017 Consolidated Statements of financial position Non Current assets - - Current Assets 195,439 99,816 Total 195,439 99,816 Non Current Liabilities - - Current Liabilities 169,843 99,726 Total 169,843 99,726 2018 2017 Consolidated Statements of comprehensive income Gross profit 33,876 797 Operating profit / (loss) 24,388 (25 ) Net Financial results 1,047 226 Comprehensive income 25,435 201

PROFIT FROM ASSOCIATES

PROFIT FROM ASSOCIATES	12 Months Ended
	Dec. 31, 2018
PROFIT FROM ASSOCIATES [Abstract]
PROFIT FROM ASSOCIATES	11. PROFIT FROM ASSOCIATES 2018 2017 2016 EGS (in liquidation) 3,101 21 175 TGU (42 ) 285 236 Link 15,148 21,335 4,678 Total 18,207 21,641 5,089

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	12 Months Ended
	Dec. 31, 2018
PROPERTY, PLANT AND EQUIPMENT [Abstract]
PROPERTY, PLANT AND EQUIPMENT	12. PROPERTY, PLANT AND EQUIPMENT 2018 C o s t D e p r e c i a t i o n Account Beginning of the year Additions Retirements Transfers End of the year Accumulated at the beginning of the year Retirements For the year Rate % Accumulated at at the end of the year Net book value Pipelines 39,112,667 - 18,101 831,882 39,926,448 18,606,656 300 959,389 2.2 19,565,745 20,360,703 Compressor plants 14,541,520 - 308,660 1,023,210 15,256,070 9,981,767 278,943 629,861 3,3 a 25 10,332,685 4,923,385 Other plants 17,219 - - - 17,219 4,642 - 584 3.3 5,226 11,993 Stations of regulation and/or measurement of pressure 1,360,656 1,081 5,948 4,001 1,359,790 1,053,505 5,163 36,195 4.0 1,084,537 275,253 Other technical installations 264,962 - 1,330 5,308 268,940 225,092 1,330 5,742 6.7 229,504 39,436 Subtotal assets related to natural gas transportation service 55,297,024 1,081 334,039 1,864,401 56,828,467 29,871,662 285,736 1,631,771 31,217,697 25,610,770 Assets related to natural gas upstream service 3,489,476 5,971 197,269 (32,913 ) 3,265,265 1,330,045 177,846 207,557 3,3 a 25 1,359,756 1,905,509 Assets related to liquids production and commercialization service 7,030,019 - 474,602 434,953 6,990,370 5,958,293 440,455 97,677 3.3 5,615,515 1,374,855 Lands 71,837 35,511 - - 107,348 - - - - - 107,348 Buildings and constructions 1,985,027 - 48,091 90,998 2,027,934 1,147,560 38,159 35,802 2.0 1,145,203 882,731 Fittings and features in building 165,920 - 11,752 17,252 171,420 67,417 6,123 7,209 4.0 68,503 102,917 Machinery, equipment and tools 513,762 129,963 47,758 10,981 606,948 396,215 47,588 27,234 6,7 a 10 375,861 231,087 UT Machinery, equipment and tools - 591 - - 591 - - 446 6,7 a 10 446 145 Computers and Telecommunication systems 3,745,839 168 1,355,581 325,263 2,715,689 3,382,394 1,350,936 192,240 6,7 a 20 2,223,698 491,991 Vehicles 263,745 38,089 5,817 - 296,017 191,683 5,503 22,310 20 208,490 87,527 Furniture 148,460 - - 104 148,564 143,026 - 837 10 143,863 4,701 Materials 1,572,902 572,326 35,953 (572,902 ) 1,536,373 - - - - - 1,536,373 Line pack 153,720 - - 222,473 376,193 17,971 - - - 17,971 358,222 Works in progress 2,229,243 6,122,710 - (2,360,610 ) 5,991,343 - - - - - 5,991,343 Total 76,666,974 6,906,410 2,510,862 - 81,062,522 42,506,266 2,352,346 2,223,083 42,377,003 38,685,519 2017 C o s t D e p r e c i a t i o n Account Beginning of the year Additions Retirements Transfers End of the year Accumulated at the beginning of the year Retirements For the year Rate % Accumulated at at the end of the year Net book value Pipelines 38,613,449 - 17,399 516,617 39,112,667 17,678,180 63 928,539 2.2 18,606,656 20,506,011 Compressor plants 14,181,525 2,660 189,100 546,435 14,541,520 9,508,571 102,860 576,056 3,3 a 25 9,981,767 4,559,753 Other plants 17,219 - - - 17,219 4,058 - 584 3.3 4,642 12,577 Stations of regulation and/or measurement of pressure 1,350,336 - - 10,320 1,360,656 1,002,347 - 51,158 4.0 1,053,505 307,151 Other technical installations 259,919 - 11,194 16,237 264,962 219,216 187 6,063 6.7 225,092 39,870 Subtotal assets related to natural gas transportation service 54,422,448 2,660 217,693 1,089,609 55,297,024 28,412,372 103,110 1,562,400 29,871,662 25,425,362 Assets related to natural gas upstream service 3,231,072 - 2,815 261,219 3,489,476 1,123,382 100 206,763 3,3 a 25 1,330,045 2,159,431 Assets related to liquids production and commercialization service 6,839,452 - 3,922 194,489 7,030,019 5,878,107 36 80,222 3.3 5,958,293 1,071,726 Lands 71,830 7 - - 71,837 - - - - - 71,837 Buildings and constructions 1,945,894 - 1,027 40,160 1,985,027 1,112,381 5 35,184 2.0 1,147,560 837,467 Fittings and features in building 165,425 - - 495 165,920 60,396 - 7,021 4.0 67,417 98,503 Machinery, equipment and tools 430,019 82,172 - 1,571 513,762 382,173 - 14,042 6,7 a 10 396,215 117,547 UT Machinery, equipment and tools - - - - - - - - 6,7 a 10 - - Computers and Telecommunication systems 3,672,719 - - 73,120 3,745,839 3,286,123 - 96,271 6,7 a 20 3,382,394 363,445 Vehicles 235,191 49,029 20,475 - 263,745 194,679 20,475 17,479 20 191,683 72,062 Furniture 148,206 - - 254 148,460 142,192 - 834 10 143,026 5,434 Materials 1,118,657 514,263 9,213 (50,805 ) 1,572,902 - - - - - 1,572,902 Line pack 153,720 - - - 153,720 17,971 - - - 17,971 135,749 Works in progress 2,190,845 1,648,510 - (1,610,112 ) 2,229,243 - - - - - 2,229,243 Total 74,625,478 2,296,641 255,145 - 76,666,974 40,609,776 123,726 2,020,216 42,506,266 34,160,708 As of December 31, 2018 and 2017, the assets allocated to the natural gas treatment and compression service include the following amounts in which the Company is a financial lease under the terms of leasing contracts: 2018 2017 Cost – Capitalized financial leasing 1,429,713 1,429,713 Accumulated depreciation (222,649 ) (130,518 ) Total 1,207,064 1,299,195 The financial leasing agreement expires in September 2026, the date on which the purchase options provided for in the contracts may be exercised.

LOANS

LOANS	12 Months Ended
	Dec. 31, 2018
LOANS [Abstract]
LOANS	13. LOANS Short-term and long-term loans as of December 31, 2018 and 2017 comprise the following: 2018 2017 Current Loans 2014 Notes - 1,758,428 2018 Notes Interest 227,114 55,614 Financial Leasing (Note 22) 215,722 148,567 Total Current loans 442,836 1,962,609 Non Current Loans 2014 Notes - 3,512,517 2018 Notes Interest 18,714,529 - Financial Leasing (Note 22) 1,439,687 1,167,494 Total non current loans 20,154,216 4,680,011 Total (1) 20,597,052 6,642,620 (1) Issuance expenses net for Ps. 120,420 and Ps. 12,584 as of December 31, 2018 and 2017, respectively. The activity of the loans as of December 31, 2018 and 2017 is the following: 2018 2017 Beginning balance 6,642,620 7,217,464 Inflation adjustment restatement (7,106,426 ) (1,478,063 ) Accrued interest 1,498,556 619,727 Effect of foreign exchange rate change 12,848,796 781,956 VAT unpaid installments 19,104 7,210 Proceeds from loans 13,821,521 - Payment of loans (1) (1,328,029 ) (125,951 ) Payment of redemption of loans (4,796,243 ) - Interest paid (2) (1,002,847 ) (379,723 ) Ending balance 20,597,052 6,642,620 (1) For the years ended on December 31, 2018 and 2017, Ps. 101,968 and Ps. 66,075 respectively were cancelled through the offseting of debit balances maintained with the creditor (Pampa Energía). (2) For the years ended on December 31, 2018 and 2017, Ps. 97,101 and Ps. 77,565, respectively, were cancelled through the offseting of debit balances maintained with the creditor (Pampa Energía). The maturities of the current and non-current loans as of December 31, 2018 are as follows, not including issuance expenses: Less than one year 212,063 From 1/01/2020 to 12/31/2020 - From 1/01/2021 to 12/31/2021 - From 1/01/2022 onwards 18,850,000 Ending balance 19,062,063 The following are the maturities of the finance leases in force as of December 31, 2018: Due: as of 12/31/2018 56,892 To due From 1/01/2019 to 12/31/2019 158,830 From 1/01/2020 to 12/31/2020 172,178 From 1/01/2021 to 12/31/2021 186,635 From 1/01/2022 to 12/31/2022 202,306 From 1/01/2023 onwards 878,568 Ending balance 1,655,409 The following table sets reconciliation between the total of future minimum lease payments as of December 31, 2018, and their present book value: As of 12/31/2019 338,887 From 1/01/2020 to 12/31/2020 282,034 From 1/01/2021 to 12/31/2021 282,034 From 1/01/2022 to 12/31/2022 282,034 From 1/01/2023 onwards 1,014,583 Total minimum future payments 2,199,572 Future financial charges on financial leases (544,163 ) Book Value financial leases 1,655,409 Issuance of notes under the 2017 Global Program (the “2017 Program”): Notes Class 1 (“2014 Notes”) The 2017 Program provides for the issuance of up to a maximum principal amount of U.S.$400 million in notes, and was authorized by resolutions of an Extraordinary Shareholders’ Meeting dated April 25, 2013, and by resolutions of its Board of Directors adopted on July 23, 2013 and December 23, 2013. The program was also authorized by the CNV on January 3, 2014, after the issuance of Resolution No. 17,262. On February 7, 2014, TGS issued the 2014 Notes according to the following characteristics: 2014 Notes Amount in U.S.$ 255,451,506 Interest rate 9.625% anual Scheduled payment date Percentage of original principal amount Amortization May 14, 2014 25% May 14, 2018 25% May 14, 2019 25% May 14, 2020 25% Frequency of Interest payment Semiannual, payable el May 14 and November 14 of each year. Guarantor None The 2014 Notes are traded in the BCBA, the MAE and the Euro MTF of the Luxembourg Exchange. The book values are based on amortized cost at an effective rate of 10.126%. As of December 31, 2018, 2014 Notes are completely canceled according to what is mentioned below. Class 2 Notes (“2018 Notes”) The General Annual Shareholders’ Meeting held on April 26, 2017, ordered the increase of up to U.S.$ 700,000,000 (or its equivalent in other currencies) of the 2017 Program authorized by the CNV by Resolution No. 17.262 dated January 3, 2014. On May 2, 2018, within the framework of the 2017 Program, the Company issued the 2018 Notes according to the following characteristics: 2018 Notes Amount in U.S.$ 500,000,000 Interest Rate 6.75% annual Issuance price 99.725% Scheduled payment date Percentage of the principal to be paid Amortization May 2, 2025 100% Frequency of interest payment Semiannual, payable on May 2 and November 2 of each year. Guarantor None The authorization for the public offering of the 2017 Program was granted by the CNV through Resolutions No. 17,262 and 18,938 dated January 3, 2014 and September 15, 2017, respectively. On October 31, 2018, through Disposition No. DI-2018-55-APN-GE#CNV, the CNV granted the extension of the 2017 Program until January 3, 2024. Funds obtained by the Company are applied to: i. The repurchase of the Class 1 Notes (the “2014 Notes”) for U.S.$ 86,511,165; ii. the cancellation and total redemption of the 2014 Notes for U.S.$ 120,786,581; iii. the balance of net funds to make investments in capital expenditures. The value of the financial debt is based on its amortized cost calculated as cash flows discounted at an effective rate of 7.088%. Covenants As of the date of issuance of these consolidated financial statements, the Company has complied with a series of restrictions derived from its current financial agreements, which include, among others, those related to obtaining new loans, payment of dividends, granting of guarantees, disposal of certain assets and make certain transactions with related parties. The Company may contract new debts under the following conditions, among others: a. To the extent that after the new debt has been incurred (i) the consolidated coverage ratio (calculated as the quotient of the consolidated adjusted EBITDA -earnings before financial results, income tax, depreciation and amortization-) and the consolidated interest expense) is equal or higher than 2.0:1; and (ii) the consolidated debt ratio (calculated as the quotient of the consolidated debt and the consolidated EBITDA) is equal to or lower than 3.5:1. b. For the refinancing of the outstanding financial debt. c. Originated by customer advances. The Company may pay dividends under the following conditions: (i) the Company is not in default under 2018 Notes, and (ii) immediately after any dividend payment, the Company may incur new debts according to the provisions in point a. of the preceding paragraph. Financial Leasing Corresponds to the financing obtained for the acquisition of the corresponding assets to the treatment and compression plant located in the area of Río Neuquén. Said agreement was concluded on August 11, 2016 with Petrobras (currently Pampa Energía) and consists of the payment of 119 consecutive monthly installments of U.S.$ 623,457 without taxes and an option to purchase for the same amount payable at the end of the 120th month of the effectiveness of the contract.

INCOME TAX AND DEFERRED TAX

INCOME TAX AND DEFERRED TAX	12 Months Ended
	Dec. 31, 2018
INCOME TAX AND DEFERRED TAX [Abstract]
INCOME TAX AND DEFERRED TAX	14. INCOME TAX AND DEFERRED TAX Tax Reform The Tax Reform sanctioned in Argentina in 2017, with some amendments introduced in December 2018 after the issuance of Law No. 27,468, brought with it a series of modifications in the taxation and calculation of the income tax to which the Company is subject in the normal course of its activities. The main changes are the following: Reduction in the applicable rate Until the fiscal year ended on December 31, 2017, the income tax rate remained at 35%. The tax reform establishes a gradual reduction of the applicable rate for the calculation of income tax, being 30% and 25% for fiscal periods beginning on January 1, 2018 and 2019 and January 1, 2020 onwards, respectively. The reduction in the applicable rate is complemented by the application of a tax on the distribution of dividends made to human persons and foreign beneficiaries, which the Company must withhold and enter the Tax authority as a single and definitive payment when the dividends are paid. This additional tax will be 7% or 13%, depending on whether the dividends distributed correspond to earnings of a fiscal period in which the Company was taxed at the rate of 30% or 25%, respectively. For these purposes it is considered, without admitting proof to the contrary, that the dividends that are made available correspond, firstly, to the oldest accumulated earnings. The effects as of December 31, 2017 of this change in the rate on the measurement of deferred assets and liabilities are detailed below in the section “Deferred tax”. Tax adjustment for inflation This section was subsequently modified by Law No. 27,468, which establishes that in the net taxable income of the periods beginning on or after January 1, 2018, the adjustment for inflation obtained by the application of the income tax law may be deducted or incorporated into the tax result for the fiscal year. This adjustment will proceed only if the percentage variation in the CPI, will accumulate (a) a percentage higher than 100% in the 36 months prior to the end of the year, or (b) regarding the first, second and third fiscal year that starts from its effective date, an accumulated variation of the CPI that exceeds 55%, 30% or 15% of said 100%, respectively. Given that the CPI for the year ended December 31, 2018 amounted to 47%, the adjustment for tax inflation mentioned in this section did not apply. Adjustment of acquisitions and investments made in fiscal years beginning on or after January 1, 2018 A cost adjustment mechanism is established for assets acquired or investments made in fiscal years beginning on or after January 1, 2018. The adjustment will be made based on the percentage variations of the WPI. This adjustment mechanism will have a significant impact on the calculation of future taxable profits on which the Company must pay the income tax. Tax revaluation It establishes the possibility of carrying out a tax revaluation, for a single time, of certain assets that are part of the assets as of December 31, 2017, in order to adjust their value and for certain assets to accelerate depreciation. This revaluation is optional, and to carry out the tax revaluation, a special tax must be paid. The special tax will vary between 8% and 15%, depending on the type of asset to be re-evaluated and it will be calculated between the difference of the residual revalued tax value and the residual tax value of origin. Once the option for a certain good is exercised, all other goods in the same category must be revalued. This tax is not deductible from income tax, and the asset increase that originates the revaluation is neither taxable for income tax nor taxable for the purposes of the TOMPI liquidation. The taxpayers that exercise the revaluation option waive to promote any judicial or administrative process for which the adjustment for tax inflation is claimed. The exercise of the revaluation option must be taken only once in the term established in the regulation. The Board of Directors has decided to make use of this option, which implies a one-time payment of Ps. 1,048,000. Said tax payable is recorded under the line “Income Tax” of the Statement of Financial Position with a charge to the current tax. On the other hand, the positive effect of the aforementioned tax revaluation on the position to be paid of the income tax for the current year and the deferred tax of future years was recorded in the “Income Tax” line of the Statement of Comprehensive Income. Deferred Tax The reconciliation between the tax computed for tax purposes and the income tax expense charged to the statement of comprehensive income in the years ended December 31, 2018, 2017 and 2016 is as follows: 2018 2017 2016 Current income tax (3,198,356 ) (2,442,608 ) (931,568 ) Special revaluation tax (1,048,000 ) - - Deferred income tax 4,233,185 2,495,685 (170,709 ) Total income tax (13,171 ) 53,077 (1,102,277 ) The analysis of the net deferred tax assets and liabilities is as follows: 2018 2017 Deferred tax assets: Deferred tax assets to be recovered after more than 12 months 725,558 619,101 Deferred tax assets to be recovered after less than 12 months 103,566 112,834 Deferred tax liabilities: Deferred tax liabilities to be recovered after more than 12 months (2,949,051 ) (7,164,720 ) Deferred tax liabilities to be recovered after less than 12 months (103,638 ) (23,965 ) Deferred tax liabilities, net (2,223,565 ) (6,456,750 ) The components of the net deferred tax assets and liabilities as of December 31, 2018, 2017 and 2016 are the following: Deferred tax assets Allowance for doubtful accounts Tax credits discounted value loss Account receivables discounted value Provisions for legal claims and other provisions Financial lease Contract liabilities Total As of December 31, 2016 12,294 2,815 70 180,950 518,070 281,232 995,431 Charge in results (12,294 ) (2,815 ) (70 ) (68,116 ) (182,606 ) 2,405 (263,496 ) As of December 31, 2017 - - - 112,834 335,464 283,637 731,935 Charge in results - 387 2,273 (11,928 ) 72,110 34,347 97,189 As of December 31, 2018 - 387 2,273 100,906 407,574 317,984 829,124 Deferred tax liabilities Deferred sales Loans Property, plant and equipment Cash and cash equivalents Inventaries Total As of December 31, 2016 85 (8,756 ) (9,915,672 ) (14,373 ) (9,150 ) (9,947,866 ) Charge in results (85 ) 5,094 2,754,614 (2,090 ) 1,648 2,759,181 As of December 31, 2017 - (3,662 ) (7,161,058 ) (16,463 ) (7,502 ) (7,188,685 ) Charge in results 2,839 (27,419 ) 4,243,088 (78,451 ) (4,061 ) 4,135,996 As of December 31, 2018 2,839 (31,081 ) (2,917,970 ) (94,914 ) (11,563 ) (3,052,689 ) Income tax expense computed at the statutory tax rate on pre-tax income differs from the income tax expense for the years ended December 31, 2018, 2017 and 2016 as follows: 2018 2017 2016 Pre tax income 11,429,007 5,698,116 2,208,572 Statutory income tax rate 30 % 35 % 35 % Pre tax income at statutory income tax rate (3,428,702 ) (1,994,341 ) (773,000 ) Tax effects due to: - Inflation effect (1) 4,432,884 (187,006 ) (321,584 ) - Special revaluation tax (1,048,000 ) - - -Change in the tax rate (2) - 2,234,656 - -Non taxable income or non deductible expenses 44,482 428 (7,693 ) -Others (13,835 ) (660 ) - Total income tax (13,171 ) 53,077 (1,102,277 ) (1) Corresponds to the inflation effect on non-deferred tax assests and liabilities.

PROVISIONS

PROVISIONS	12 Months Ended
	Dec. 31, 2018
PROVISIONS [Abstract]
PROVISIONS	15. PROVISIONS For legal claims and others (1) Balances as of 12/31/2016 408,002 Inflation adjustment restatement (80,163 ) Additions 225,887 ´(1) Uses (254,858 ) Reversals (8,967 ) ´(3) Balances as of 12/31/2017 289,901 Inflation adjustment restatement (112,740 ) Additions 195,156 ´(1) Uses (787 ) Reversals (362 ) ´(2) Balances as of 12/31/2018 371,168 (1) Ps. 107,419 and Ps. 152,635 are included in “Other operating expenses” and Ps. 118,468 and Ps. 77,472 in “Financial expenses” for the years ended on December 31, 2018 and 2017, respectively. (2) The total amount is recorded in “Other operating income” (3) Ps. 2,263, are included in “Other operating expenses” and Ps. 6,704 in “Financial expenses” for the year 2017. The total amount of the Provisions are included in current liabilities.

FINANCIAL RISK MANAGEMENT

FINANCIAL RISK MANAGEMENT	12 Months Ended
	Dec. 31, 2018
FINANCIAL RISK MANAGEMENT [Abstract]
FINANCIAL RISK MANAGEMENT	16. FINANCIAL RISK MANAGEMENT 1. Financial risk factors The Company’s activities and the market in which it operates expose it to a series of financial risks: market risk (including foreign exchange risk, interest rate risk, and commodity price risk), credit risk and liquidity risk. To that extent, the Company has different policies adopted to mitigate its exposure to financial risks. 1.1 Foreign exchange risk The Company is primarily exposed to the fluctuation of the exchange rate of the U.S. dollar against the Argentine Peso due to the fact that almost its entire financial indebtedness is denominated in U.S. dollars. The exposure to other currencies is not significant. As regards to the revenue derived from the Natural Gas Transportation segment, the tariffs charged by the Company are currently denominated in Argentine pesos. On the other hand, revenues in US dollars derived from the Liquids Production and Commercialization segment accounted for approximately 77%, 76% and 79% of the segment’s total revenues for the years ended December 31, 2018, 2017 and 2016, respectively. Total revenues denominated in Argentine Pesos accounted for 59%, 51% and 43% for the years ended December 31, 2018, 2017 and 2016, respectively. TGS’s financial risk management policies are defined with the objective of mitigating the impact that the variation in the exchange rate has on the Company’s position in foreign currency. For this purpose, alternative investment evaluations are regularly carried out to diversify investments in financial instruments portfolio between US dollar-denominated instruments or, although denominated in Argentine pesos, to obtain positive returns in real terms. Additionally, in the event that it is considered appropriate, the Company contracts derivative financial instruments that allow TGS to hedge the fluctuation of the US dollar over long-term positions in such currency. As of December 31, 2018, for mitigating this foreign exchange risk, 74% of the Company’s fund placements are denominated in US dollars. Considering the net liability financial position described in the table below, the Company estimated that, other factors being constant, a 10% appreciation of the US dollar against the Argentine Peso for the years ended December 31, 2018, 2017 and 2016 would have decreased the Company’s income before tax for the year in approximately Ps. 739,849, Ps. 259,923, and Ps. 365,543, respectively. A 10% depreciation of the US dollar against the Argentine Peso would have an equal and opposite effect on the pre-tax income. Actual results may differ significantly from these theoretical sensitivity scenarios. Net assets / liabilities position in USD 2018 2017 2016 Assets 394,369 192,764 88,463 Liabilities (588,525 ) (286,129 ) (317,952 ) Total (194,156 ) (93,365 ) (229,489 ) Effect on financial results in $ Pesos 739,849 259,923 365,543 Total 739,849 259,923 365,543 1.2 Interest rate risk The management of interest rate risk seeks to reduce financial costs and limit the Company’s exposure to an increase in interest rates. Currently, the Company’s exposure to interest rate risk is limited due to the fact that 100% of its outstanding financial indebtedness bears fixed interest rates. The interest rate profile of the Company’s borrowings is set out in Note 13. The main objective of the Company’s financial investment activities is to obtain the highest return by investing in low risk and high liquidity instruments. The Company maintains a short-term portfolio of cash equivalents and investments made up of investments in mutual funds and deposits in remunerated bank accounts, public and private securities. The risk of these instruments is low given the short-term nature and high liquidity in well-known financial institutions. As a consequence of the application of IAS 29, maintaining monetary assets generates loss of purchasing power, provided that such items are not subject to an adjustment mechanism that compensates to some extent the loss of purchasing power. This loss of purchasing power is included in the result of the period under gain on the net monetary position. On the contrary, maintaining monetary liabilities generates a gain in purchasing power, which are also included in such line item. The Company’s risk management policy is defined with the objective of reducing the impact of the loss of purchasing power. During the 2016, 2017 and 2018 fiscal years the Company has maintained a liability monetary position. As a consequence, TGS has recorded a a net gain from exposure to inflation in the monetary items. The following table shows a breakdown of the Company’s fixed-rate and floating-rate financial assets and liabilities as of December 31, 2018 and 2017: Financial assets (1) Financial liabilities (2) 2018 2017 2018 2017 Fix interest rate 8,525,212 3,097,259 18,941,643 5,326,559 Variable interest rate 14,473 31,868 - - Total 8,539,685 3,129,127 18,941,643 5,326,559 (1) Includes mutual funds, LETES, Lebacs and bank accounts. Trade receivables do no bear interests, except for Ps. 14,473 and Ps. 31,868, which bears CER plus a spread of 8% as of December 31, 2018 and 2017, respectively. (2) Includes loans, issuance expenses and financial leasing In view of the nature of the Company’s financial assets which bear variable interest, an immediate 100 basis points decrease in the interest rate would not have a significant impact on the total value of the financial assets. 1.3 Commodity price risk Commercial operations performed by the Company in its Liquids Production and Commercialization segment are affected by a number of factors beyond its control, including changes in the international prices of the products sold, and government regulations on prices, taxes and other charges, among others. The sale prices of propane and butane (“LPG”) and natural gasoline the Company exports in its Liquids Production and Commercialization segment are referenced to international prices (Mont Belvieu for the LPG and NWE ARA for the natural gasoline). Additionally, approximately 59% of the total sales of propane and butane that are made in the domestic market are made at prices fixed by the Hydrocarbon Resources Secretariat (“SRH” for its acronym in Spanish) based on export parity prices. These prices have historically been cyclical, reflecting overall economic conditions and changes in capacity within the industry, which may affect the profitability of TGS. Based on the volume of sales for the years ended December 31, 2018, 2017 and 2016, the Company estimated that, other factors being constant, a decrease of U.S.$50/ton in the international price of LPG and natural gasoline, respectively, would have decreased the Company’s net comprehensive income in its Liquids Production and Commercialization segment in Ps. 552,004, Ps.449,231 and Ps. 233,323 respectively. On the other hand, an increase of U.S.$50/ton in the international price would have had the opposite effect. Derivated financial instruments On July 23, 2018, TGS entered into an agreement with a recognized financial institution to hedge export prices for propane, butane and natural gasoline (put contracts), in order to offset potential losses that could arise if export prices fall below breakeven prices (those that balance costs). This agreement is valid between October 2018 and April 2020, according to the following monthly short tons: Period Propane Butane Natural gasoline October 2018 – April 2019 6,045 4,506 2,700 May 2019 – September 2019 - - 4,100 October 2019 9,068 7,010 4,200 November 2019 – April 2020 13,098 10,014 6,000 In order to arrange such operation, the Company paid a premium of U.S.$ 3 million, which was classified as a financial asset measured at fair value through profit or loss, being recorded under “Derivative financial instruments”. Thus, the Company has not designated those instruments for the application of hedge accounting in accordance with the provisions of IFRS 9. As of December 31, 2018, the balance is Ps. 218,272 and is recorded under the item “Derivative Financial instruments”. 1.4 Credit risk The Company’s exposures to credit risk takes the form of a loss that would be recognized if counterparties failed to, or were unable to, meet their payment obligations. These risks may arise in certain agreements in relation to amounts owed for physical product sales, the use of derivative instruments, and the investment of surplus cash balances. This risk mainly results from economic and financial factors or from a possible default of counterparty. The Company is subject to credit risk arising from outstanding receivables, cash and cash equivalents and deposits with banks and financial institutions, and from the use of derivative financial instruments. The Company’s policy is to manage credit exposure to trading counterparties within defined trading limits. Trade and Other Receivables If any of the Company’s customers are independently rated, these ratings are used. Otherwise, if there is no independent rating, the Company assesses the credit quality of the customer taking into account its financial position, past experience and other factors. The Company may seek cash collateral, letter of credit or parent company guarantees, as considered appropriate. As of December 31, 2018 and 2017, the balance of current and non-current trade receivables, net of allowances of doubtful accounts are as follows: 2018 2017 Current trade receivables 3,247,020 3,002,432 Non-current trade receivables - 4,511 Allowances for doubful accounts (132,521 ) - Total 3,114,499 3,006,943 The Company, in the normal course of business, renders natural gas transportation services, principally to gas distribution companies, CAMMESA and to Pampa Energía. Significant customers in terms of revenues and trade receivables (net of allowances of doubtful accounts) from natural gas transportation for the years ended December 31, 2018, 2017 and 2016 are as follows: 2018 2017 2016 Revenues Trade receivables Revenues Trade receivables Revenues MetroGas 3,222,608 375,580 1,916,408 309,208 1,166,861 Camuzzi Gas Pampeana S.A. 2,393,722 279,663 1,408,811 226,138 702,375 Naturgy Argentina 1,931,580 239,730 1,012,029 172,665 524,030 CAMMESA 1,337,714 183,249 889,716 232,175 651,592 Pampa Energía 439,556 91,684 44,683 1,302 43,034 Camuzzi Gas del Sur S.A. 534,462 56,928 310,222 46,319 156,503 Revenues from Liquids Production and Commercialization customers (including those made on behalf of third parties, from whom the Company earns a commission and trade receivables (net of allowances of doubtful accounts) for the years ended December 31, 2018, 2017 and 2016 are as follows: 2018 2017 2016 Revenues Trade receivables Revenues Trade receivables Revenues PBB Polisur 5,267,302 708,797 3,683,956 520,645 3,565,562 Petredec 858,846 - 1,377,647 433,916 - Geogas Trading S.A. 1,102,307 - 571,260 - 931,432 Shell Trading (US) Company 89,868 - 1,425,123 276,932 - Petrobras Global Trading BV 1,743,806 137,413 - - - Petroleo Brasileiro - - - - 546,476 Braskem Netherlands B.V. - - - - 42,611 Cash and financial placements The Company is exposed to counterparty credit risk on cash and cash equivalent balances. The Company holds cash on deposit with a number of financial institutions. The Company manages its credit risk exposure by limiting individual deposits to clearly defined limits in various financial institutions. The Company considers that this risk is limited because it has short-term funds policies whose main objective is to obtain an adequate return in terms of market characteristics and minimizing exposure. The Company only deposits with high quality banks and financial institutions with a high credit rating. The maximum exposure to credit risk is represented by the carrying amount of cash and cash equivalents in the statement of financial position. Below is a detail of the maturities of the financial assets included in: (i) cash and cash equivalents, (ii) other financial assets, (iii) trade receivables, (iv) other receivables and (v) derivate financial instruments, as of December 31, 2018 and 2017: December 31-2018 Cash and cash equivalents Other financial assets Receivables (1) (2) Without specified maturity 14,485,525 - 467 With specified maturity Overdue Until 12-31-2017 - - 133,771 From 01-01-18 to 03-31-18 - - 310 From 04-01-18 to 06-30-18 - - 4,020 From 07-01-18 to 09-30-18 - - 11,400 From 10-01-18 to 12-31-18 - - 535,609 Total overdue - - 685,110 Non-due From 01-01-19 to 03-31-19 2,159,302 219,767 2,945,285 From 04-01-19 to 06-30-19 - 1,495 41,157 From 07-01-19 to 09-30-19 - 1,495 - From 10-01-19 to 12-31-19 - 1,229 - During 2020 - 3,357 5,529 During 2021 - 3,044 - During 2022 - 1,911 - During 2023 - 448 - From 2024 onwards - - - Total non-due 2,159,302 232,746 2,991,971 Total with specified maturity 2,159,302 232,746 3,677,081 Total 16,644,827 232,746 3,677,548 (1) (2) December 31-2017 Cash and cash equivalents Other financial assets Receivables (1) (2) Without specified maturity 2,943,101 - 685 With specified maturity Overdue Until 12-31-2016 - - 2,990 From 01-01-17 to 03-31-17 - - 202 From 04-01-17 to 06-30-17 - - 2,637 From 07-01-17 to 09-30-17 - - 18,736 From 10-01-17 to 12-31-17 - - 220,135 Total overdue - - 244,700 Non-Due From 01-01-18 to 03-31-18 973,646 591,525 3,017,756 From 04-01-18 to 06-30-18 - 1,533,148 3,703 From 07-01-18 to 09-30-18 - 332,232 3,188 From 10-01-18 to 12-31-18 - 2,364 3,839 During 2019 - 8,436 17,624 During 2020 - 4,954 - During 2021 - 4,494 - During 2022 - 2,822 - From 2023 onwards - 663 - Total non-due 973,646 2,480,638 3,046,110 Total with specified maturity 973,646 2,480,638 3,290,810 Total 3,916,747 2,480,638 3,291,495 (1) (2) 1.5 Liquidity risk The Company is exposed to liquidity risks, including: risks associated with refinancing borrowings as they mature, the risk that borrowing facilities are not available to meet cash requirements and the risk that financial assets cannot readily be converted to cash without loss of value. Failure to manage financing risks could have a material impact on the Company’s cash flow and statement of financial position. The Company has funding policies whose main objectives are to meet the financing needs at the lowest cost possible according to market conditions. The main objective of the Company is its financial solvency. Given the current financial market conditions, the Company believes that the availability of resources (including available credit lines) and the positive cash flow from operations are sufficient to meet its current obligations. Additionally, TGS applies a methodology for analyzing and assigning credit limits to individual financial institutions in order to minimize the associated credit risk. In line with this, the Company invests its liquid funds in certain financial institutions with an appropriate credit rating. The tables below include a detail of the maturities of the obligations corresponding to financial liabilities corresponding to: trade payables, payroll payables, other payables and loans as of December 31, 2018 and 2017. The amounts disclosed in the table are the contractual undiscounted cash flows and as a result, they do not reconcile to the amounts disclosed on the statement of financial position. These tables are made based on available information at the end of each year and may not reflect the actual amounts in the future. Therefore, the amounts disclosed are provided for illustrative purposes only: December 31, 2018 Loans Other financial liabilities Financial Leases Without specified maturity - - - With specified maturity Overdue Until 12-31-2017 - 103,597 - From 01-01-18 to 03-31-18 - 311 - From 04-01-18 to 06-30-18 - 311 - From 07-01-18 to 09-30-18 - 311 - From 10-01-18 to 12-31-18 - 311 56,891 Total overdue - 104,841 56,891 Non-due From 01-01-19 to 03-31-19 - 3,352,746 70,499 From 04-01-19 to 06-30-19 636,188 21,739 70,499 From 07-01-19 to 09-30-19 - - 70,499 From 10-01-19 to 12-31-19 636,188 - 70,499 During 2020 1,272,375 - 282,034 During 2021 1,272,375 - 282,034 During 2022 1,272,375 - 282,034 During 2023 1,272,375 - 282,034 From 2024 onwards 20,758,563 - 732,549 Total non-due 27,120,439 3,374,485 2,142,681 Total with specified maturity 27,120,439 3,479,326 2,199,572 Total 27,120,439 3,479,326 2,199,572 December 31, 2017 Loans Other financial liabilities Financial Leases Without specified maturity - - - With specified maturity Overdue Until 12-31-2016 - 109,528 - From 01-01-17 to 03-31-17 - 459 - From 04-01-17 to 06-30-17 - 459 - From 07-01-17 to 09-30-17 - 459 - From 10-01-17 to 12-31-17 - 459 41,545 Total overdue - 111,364 41,545 Non-Due From 01-01-18 to 03-31-18 - 2,300,495 51,490 From 04-01-18 to 06-30-18 2,012,300 125,344 51,490 From 07-01-18 to 09-30-18 - - 51,490 From 10-01-18 to 12-31-18 169,249 - 51,490 During 2019 2,012,300 - 205,985 During 2020 1,843,053 - 205,985 During 2021 - - 205,985 During 2022 - - 205,985 From 2023 onwards - - 741,035 Total non-due 6,036,902 2,425,839 1,770,935 Total with specified maturity 6,036,902 2,537,203 1,812,480 Total 6,036,902 2,537,203 1,812,480 1.6 Capital risk management The objective of the Company in capital management are to safeguard the ability to continue as a going concern, achieve an optimal cost of capital structure and support the capital expenditures process in order to provide returns to the shareholders and benefits for other stakeholders. The Company seeks to maintain a level of cash generation from operating activities, which may allow it to meet all of its commitments. The Company monitors capital on the basis of the gearing ratio. This ratio is calculated as total financial debt (including current and non-current loans as shown in the consolidated statement of financial position, if applicable) divided by total capital. Total capital is calculated as equity, as shown in the consolidated statement of financial position, plus total debt. During the year ended December 31, 2018 and 2017, the gearing ratio was as follows: 2018 2017 Total debt (Note 13) 20,597,052 6,642,620 Total Equity 30,945,305 25,279,589 Total Capital 51,542,357 31,922,209 Gearing Ratio 0.40 0.21 2 FINANCIAL INSTRUMENTS BY CATEGORY AND HIERARCHY 2.1 Financial instrument categories Accounting policies for the categorization of financial instruments are explained in Note 4.d. According to the provisions of IFRS 7, IAS 32 and IFRS 9 (IAS 39 as of December 31, 2017), non-financial assets and liabilities such as PPE, investments in associates, inventories, advances from customers, deferred income tax, taxes and social taxes payables and provisions are not included. The categories of financial assets and liabilities as of December 31, 2018 and 2017 are as follows (According to the chosen transition method, the comparative information has not been restated. See Notes 3 and 4.d): December 31, 2018 Financial assets at fair value Financial assets held to maturity Total CURRENT ASSETS Trade receivables - 3,114,499 3,114,499 Other receivables - 424,339 424,339 Derivative financial instruments 218,272 - 218,272 Other financial assets at amortized cost - 5,714 5,714 Cash and cash equivalents 2,161,167 14,483,660 16,644,827 Total current assets 2,379,439 18,028,212 20,407,651 NON-CURRENT ASSETS Other receivables - 6,189 6,189 Other financial assets at amortized cost - 8,760 8,760 Total non-current assets - 14,949 14,949 Total assets 2,379,439 18,043,161 20,422,600 Financial liabilities at fair value Other financial liabilities Total CURRENT LIABILITIES Trade payables - 3,092,037 3,092,037 Loans - 442,836 442,836 Payroll and social security taxes payables - 309,351 309,351 Other payables - 80,674 80,674 Total current liabilities - 3,924,898 3,924,898 NON-CURRENT LIABILITIES Loans - 20,154,216 20,154,216 Total non-current liabilities - 20,154,216 20,154,216 Total liabilities - 24,079,114 24,079,114 December 31, 2017 Financial assets at fair value Financial assets held to maturity Loans and other receivables Total CURRENT ASSETS Trade receivables - - 3,002,432 3,002,432 Other receivables - - 270,464 270,464 Other financial assets at amortized cost - 2,123,611 10,500 2,134,111 Other financial assets at fair value through profit or loss 325,158 - - 325,158 Cash and cash equivalents 1,960,696 - 1,956,051 3,916,747 Total current assets 2,285,854 2,123,611 5,239,447 9,648,912 NON-CURRENT ASSETS Trade receivables - - 4,511 4,511 Other receivables - - 14,088 14,088 Other financial assets at fair value through profit or loss - - 21,369 21,369 Total non-current assets - - 39,968 39,968 Total assets 2,285,854 2,123,611 5,279,415 9,688,880 Financial liabilities at fair value Other financial liabilities Total CURRENT LIABILITIES Trade payables - 2,145,738 2,145,738 Loans - 1,962,609 1,962,609 Payroll and social security taxes payables - 282,973 282,973 Other payables - 49,531 49,531 Total current liabilities - 4,440,851 4,440,851 NON-CURRENT LIABILITIES Loans - 4,680,011 4,680,011 Total non-current liabilities - 4,680,011 4,680,011 Total liabilities - 9,120,862 9,120,862 2.2 Fair value measurement hierarchy and estimates According to IFRS 13, the fair value hierarchy introduces three levels of inputs. These levels are: • Level 1: includes financial assets and liabilities whose fair values are estimated using quoted prices (unadjusted) in active markets for identical assets and liabilities. The instruments included in this level primarily include balances in mutual funds and public or private bonds listed on the BYMA. The mutual funds mainly carry out their placements in bonds issued by the Central Bank of the Argentine Republic. • Level 2: includes financial assets and liabilities whose fair value is estimated using different assumptions quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. as prices) or indirectly (for example, derived from prices). Within this level, the Company includes those derivate financial instruments for which it was not able to find an active market. • Level 3: includes financial instruments for which the assumptions used in estimating fair value are not based on observable market information. During 2018, there were neither transfers between the different hierarchies of fair values nor reclassifications between financial instruments categories. The table below shows different assets and liabilities at their fair value classified by hierarchy as of December 31, 2018 and 2017: December 31, 2018 Level 1 Level 2 Level 3 Total Financial assets at fair value Cash and cash equivalents 2,161,167 - - 2,161,167 Derivative financial instruments - 218,272 - 218,272 Total 2,161,167 218,272 - 2,379,439 December 31, 2017 Level 1 Level 2 Level 3 Total Financial assets at fair value Cash and cash equivalents 1,960,696 - - 1,960,696 Other current financial assets at fair value through profit or loss 325,158 - - 325,158 Total 2,285,854 - - 2,285,854 The fair value of the financial assets and liabilities is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As of December 31, 2018, the carrying amount of certain financial instruments used by the Company including cash, cash equivalents, other investments, receivables, payables and short-term loans are representative of fair value because of the short-term nature of these instruments. The following table reflects the carrying amount and estimated fair value of the 2018 Notes as of December 31, 2018, based on their quoted market price: Carrying amount Fair value 2018notes 18,941,643 17,200,060

REGULATORY FRAMEWORK

REGULATORY FRAMEWORK	12 Months Ended
	Dec. 31, 2018
REGULATORY FRAMEWORK [Abstract]
REGULATORY FRAMEWORK	17. REGULATORY FRAMEWORK a) General framework of the natural gas transportation segment General aspects Regarding TGS’ Natural Gas Transportation business, it is regulated by Law No. 24,076 (“the Natural Gas Act”), its regulatory Decree No. 1,738/92 and the Regulatory framework for the transportation and distribution of natural gas in Argentina. The Natural Gas Act created ENARGAS, which is entitled, among other things, to set the basis for the calculation, monitoring, approval of tariffs and the power to verify compliance with the Natural Gas Law and its regulations. On January 28, 2016, Resolution No. 7 of the MINEM of Argentina repealed the Resolution 2000/2005 of the former Ministry of MPFIPyS which provided that all tariff increases should have the prior intervention of the Undersecretary of Coordination and Management Control. TGS License has been granted for an original period of 35 years beginning on December 28, 1992. However, the Natural Gas Act provides that TGS may apply to ENARGAS for a renewal of its license for an additional period of ten years. ENARGAS should evaluate at that time the performance of TGS and raise a recommendation to the Executive Branch. At the end of the period of validity of the license, 35 or 45, as appropriate, the Natural Gas Act requires a call for a new tender for the granting of a new license, in which TGS, provided the Company fulfilled substantially with the obligations resulting from the license, would have the option of matching the best offer that the Government received in this bidding process. Tariff situation Prior the enactment of the Public Emergency Law, and according to the Regulatory Framework, transportation tariffs were to be calculated in US dollars and converted into Argentine pesos at the time the customer was billed using the exchange rate prevailing at the date of the billing. The basic natural gas transportation tariffs charged by TGS had been established at the time of the privatization of GdE and were to be adjusted, subject to prior authorization, in the following cases: (i) semiannually to reflect changes in the US producer price index (“PPI”) and (ii) every five years according to efficiency and investment factors determined by ENARGAS. The “efficiency factor” was a reduction to the base tariff resulting from future efficiency programs while the “investment factor” increased the tariffs to compensate the licensees for future investments which were not repaid through tariffs. Also, subject to ENARGAS approval, tariffs were to be adjusted to reflect non-recurrent circumstances or tax changes, other than income tax. The terms and conditions as described in the precedent paragraph in connection with tariff adjustments contemplated within the Regulatory Framework are no longer effective since the enactment of the Public Emergency Law in early 2002, which, among other provisions, eliminated tariff increases based on US dollar exchange rate fluctuations, foreign price indexes or any other indexing procedure and established a conversion rate of one peso to one US dollar for tariffs. The Public Emergency Law also granted the Executive Branch power to renegotiate contracts entered into with private utility companies, pursuant to the framework included in such law as long as it is in force, which expired on December 31, 2017, after several extensions. In July 2003, the former Unit for Renegotiation and Assessment of Utilities Contracts (“ex UNIREN”) was created under the joint jurisdiction of the Ministry of Economy and Finance and the Ministry of Federal Planning, Public Investment and Services (“ex MPFIPyS”). Ex UNIREN conducted the renegotiation process of the contracts related to utilities and public works, and was entitled to enter into total or partial agreements with the licensees and submit projects regulating the transitory adjustment of tariffs and prices, among other things. As provided in the Public Emergency Law, TGS should have reached a consensus with the ex UNIREN on the modalities, terms and dates for signing the comprehensive agreement before its due date. In the event that such a consensus was not reached, ex UNIREN should have submitted a report to the Executive Branch with recommendations of the next steps to follow in the future. On February 16, 2016, the Executive Branch issued Decree No. 367/2016. It established the dissolution of the ex UNIREN and transferred to each ministry the responsibility to renegotiate public service agreements. In our case, the MINEM together with the Ministry of Economy (“MH”). On March 30, 2017, within the framework of the tariff renegotiation process mentioned above, the Company entered into the Integral Renegotiation Agreement (the “2017 Integral Agreement”) which contained similar terms and conditions to those set forth in the agreements signed in 2008, 2011 and 2015. The 2017 Integral Agreement had as background the transitional agreements celebrated in 2008, 2016 and 2017 (the “Transitional Agreements”) by which TGS was granted with transitional tariff schedule applicable in order to continue providing the service of natural gas transportation service. On March 27, 2018, the Executive Branch of the Argentine Government issued the Decree No. 250/2018 (the “Decree 250”) ratifying the 2017 Integral Agreement. This decree represents the conclusion of the Integral Tariff Review process (“RTI” for its acronym in Spanish) and the completion of the 2017 Transitional Agreement, and thus, the final renegotiation of the license after seventeen years of negotiations. The 2017 Integral Agreement sets the guidelines for the provision of the natural gas transportation service until the end of the License. Among these guidelines: • The RTI Process, • The Five-Year Investment Plan was approved. amount to Ps. 6,786,543,expressed in December 31, 2016 currency terms • A non-automatic six-month adjustment mechanism for the natural gas transportation tariff and the investment commitments were approved. This adjustment must be approved by ENARGAS and for its calculation, the evolution of the WPI published by INDEC will be considered. • TGS and its shareholders must withdraw any claim against the Government related to the natural gas transportation business, including the arbitration proceedings before the ICSID. The Company desisted from it on June 26, 2018. As it is mentioned above the tariff increase was granted in 3 installments according to the following resolutions: • Effective as of April 1, 2017, 64.2% of the tariff for the natural gas transport service, the CAU not being adjusted, in accordance with the provisions of Resolution No. 4362/2017 (“Resolution 4362 “). • Effective as of December 1, 2017, after the issuance of Resolution 120, 81.1% on the tariff for the natural gas transport service and 29.7% on the CAU, which includes the first adjustment by WPI. • Effective as of April 1, 2018, an increase of 50% over the tariff for the natural gas transport service and the CAU within the framework of the provisions of Resolution No. 310/2018 issued by ENARGAS. In addition, completing the RTI process, prior to the ratification of the 2017 Integral Agreement and within the framework of the Transitional Agreements, the Company received the following tariff increases: • Through Resolution ENARGAS I-2852/2014 (“Resolution I-2852”) on April 7, 2014, a staggered increase of 8% was established as of April 1, 2014, from 14% accumulated since 1 June 2014 and 20% accumulated since August 1, 2014. • On June 5, 2015, ENARGAS issued Resolution No. I-3347/2015 (“Resolution I-3347”), which complements Resolution I-2852, which approved an increase in the tariffs applicable to the natural gas transportation service from May 1, 2015. This increase represented for TGS a transitional increase of 44.3% in the price of the natural gas transport service and 73.2% in the CAU. • Effective since April 1, 2016, an increase of 200.1% on the rates applicable to the public service of Natural Gas Transportation and to the CAU (the “2016 Increase”) in accordance with the provisions of Resolution No. I-3724/2016 of ENARGAS (“Resolution 3724”), which could only be invoiced in full from October 7, 2016 after the ruling issued by the Supreme Court of Justice of the Nation (“CSJN”) that determined the nullity of Resolutions No. 28/2016 and 31/2016 (jointly “Resolutions 28 and 31”) of the former Ministry of MINEM. Semiannual tariff increase This increase is granted within the framework of the semiannual tariff adjustment of the natural gas transportation service in accordance with the provisions of the RTI process. In the public hearing held on September 4, 2018, in which the Company requested, based on the variation of the WPI recorded for the period February - August 2018, a tariff increase of approximately 30%. Considering the hearing, on September 27, 2018, ENARGAS issued Resolution No. 265/2018 which determined a 19.7% tariff increase effective as of October 1, 2018. This increase was determined by ENARGAS based on the simple average of the WPI, the Construction Cost Index for the period February and August 2018 and the Salary Variation Index between December 2017 and June 2018. It is noteworthy that ENARGAS supported the determination of the aforementioned tariff increase in the provisions of Resolution 4362, which, among other issues, provided that under certain circumstances and macroeconomic conditions, such as the significant devaluation occurred after April 2018, ENARGAS may use other indexes than the WPI to determine the tariff increase. TGS notified ENARGAS its disagreement with respect to the methodology for calculating the semiannual adjustment. On February 26, 2019, within the framework of the RTI, a new public hearing took place with the aim of the determination of the biannual tariff increase that will come into effect as of April 1, 2019. On March 29, 2019, ENARGAs issued Resolution No. 192/2019 whereby ENARGAS approves, effective April 1, 2019, a 26% tariff increase. b) Regulatory Framework for non-regulated segments Domestic market The Production and Commercialization of Liquids segment is not subject to regulation by ENARGAS, and as it is provided in the Transfer Agreement, is organized as a separate business unit within TGS, keeping accounting information separately. However, over recent years, the Argentine Government enacted regulations which significantly impacted on it. In April 2005, the Argentine Government enacted Law No. 26,020 which sets forth the regulatory framework for the industry and commercialization of LPG. Among other things, the Law No. 26,020 creates the On March 30, 2015, the Executive Branch issued Decree No. 470/2015, regulated by Resolution No. 49/2015 issued by the Federal Energy Bureau, which created the Programa Hogares con Garrafa (the “Households with Bottles Program”) which replaced the programs in force until that time. The Households with Bottles Program was implemented through Resolutions No. 49/2015 and No. 470/2015 issued by the Federal Energy Bureau. In line with the previous programs, the Households with Bottles Program sets a maximum reference price for the members of the marketing chain in order to guarantee the supply to low-income residential user, by committing the LPG producers to supply at a fixed price (below the market price) with a quota assigned to each producer. Additionally, payment of compensation to the participating producers of the Households with Bottles Program was established. Under the Households with Bottles Program the SHR regulates the price and the quantity of LPG sold in the domestic market by each LPG producer. During 2017, the SHR issued Resolutions No. 56-E/2017 and No. 287-E/2017, setting the prices at Ps. 2,568 per ton of butane and Ps. 2,410 per ton of propane as of April 2017 and at Ps. 4,302 per ton of butane and Ps. 4,290 per ton of propane as of December 1, 2017. For 2016 and the first quarter of 2017, the price was set by Resolution No. 70/2015 in Ps. 650 per ton. On March 27, 2018, the SRH issued Resolution No. 5/2018, which increases as from April 1, 2018, the price of the products contributed to the Households with Bottles Program to Ps. 5,416 and Ps. 5,502 per ton of butane and propane, respectively. On the other hand, the compensation received from the National Government remained at Ps. 550/tn. Finally, on January 28, 2019, the Energy Government Secretariat issued Resolution No. 15/2019 modifying the price for which the products contributed to the Households with Bottles Program are sold. As of February 1, 2019, the price increased to Ps. 9.154 and Ps. 9,042 per ton of butane and propane, respectively, eliminating the compensation received by the Argentine government. In this context, the Company has filed various administrative and judicial claims challenging the general regulations of the program, as well as the administrative acts that determine the volumes of butane that must be sold in the domestic market, in order to safeguard its economic-financial situation and thus, preventing that this situation does not extend over time. In addition, the Company is a party of the Propane Gas Supply Agreement for Induced Propane Gas Distribution Networks (“Propane for Networks Agreement”) entered into with the Argentine Government by which it undertakes to supply propane to the domestic market at a lower price to the market. In compensation, the Company receives an economic compensation calculated as the difference between the sales price and the export parity determined by the former Ministry of MINEM. In 2017, the MINEM issued Resolutions No. 74 and 474-E/2017 (“ Resolution 474 Finally, in May 2018, the Company signed the sixteenth extension by which the methodology for determining the price and volumes for the period April 1, 2018 - December 31, 2019 is established. During 2018, 2017 and 2016, the Company booked the amount of Ps. 406,727, Ps. 347,655 and Ps. 314,028, for subsidies for the programs mentioned above, respectively. As of December 31, 2018, the Argentine Government owes the Company Ps. 292,866 for these concepts. Foreign market On September 3, 2018, the Executive Branch issued Decree No. 793/2018, which, between September 4, 2018 and December 31, 2020, sets an export duty of 12% on the exported amount of propane, butane and natural gasoline. This withholding is capped at $4 for each dollar of the tax base or the official FOB price. Decree No. 2,067 / 08 Through Presidential Decree No. 2,067/08, the Executive Branch created a tariff charge to be paid by (i) the users of regulated services of transportation and / or distribution, (ii) natural gas consumers receiving natural gas directly from producers without making use of transportation systems or natural gas distribution, (iii) the natural gas processing companies in order to finance the import of natural gas. The tariff charge sets forth in this decree finance the higher price of the natural gas imports required to compensate the injection of natural gas necessary to meet national requirements (the “Charge”). When the Charge was created, TGS paid it in accordance with the provisions of Resolution I-563/2008, at Ps. 0.0492/m3. The payment of the natural gas processing tariff charge was selectively subsidized from 2008 according to the destination of the natural gas. In November 2011, however, ENARGAS issued Resolution No. 1,982/11 and 1,991/11 (the “Subsidy Beneficiaries Resolutions”) which modified the list of the subsidy beneficiaries, and thus, involved a cost increase for many of our clients and for us (for certain of our consumption for our own account). The natural gas processing tariff charge increased from Ps. 0.049 to Ps. 0.405 per cubic meter of natural gas effective from December 1, 2011, representing a significant increase in our variable costs of natural gas processing. In order to avoid this damage, TGS appealed against the Presidential Decree and the Resolutions including National Government, ENARGAS and ex MPFIPyS as defendants. For further information regarding the legal action filed the Company, see Note 20.b. On March 28, 2016, the MINEM issued Resolution No. 28/16 (“Resolution 28”), which instructs ENARGAS to take all the necessary measures to derogate the tariff charge created by Decree No. 2,067/08 as from April 1, 2016. However, such Resolution does not repeal or declare illegitimate this decree and the Subsidy Beneficiaries Resolutions for which the judicial action is still ongoing. c) Essential assets A substantial portion of the assets transferred by GdE has been defined as essential for the performance of the natural gas transportation service. Therefore, TGS is required to keep separated and maintain these assets, together with any future improvements, in accordance with certain standards defined in the License. TGS may not, for any reason, dispose of, encumber, lease, sublease or loan essential assets nor use such assets for purposes other than the provision of the licensed service without ENARGAS´s prior authorization. Any expansion or improvements that it makes to the gas pipeline system may only be encumbered to secure loans that have a term of more than one year to finance such extensions or improvements. Upon expiration of the License, TGS will be required to transfer to the Argentine government or its designee, the essential assets listed in an updated inventory as of the expiration date, free of any debt, encumbrances or attachments. If the Company decides not to continue with the license, TGS will receive a compensation equal to the lower of the following two amounts: i) the net book value of the essential assets determined on the basis of the price paid by the acquiring joint arrangements, and the original cost of subsequent investments carried in US dollars and adjusted by the PPI, net of accumulated depreciation according to the calculation rules to be determined by ENARGAS; or ii) the net proceeds of a new competitive bidding (the “New Bidding”). Once the period of the extension of the License expires, TGS will be entitled to participate in the New Bidding, and thus, it shall be entitled to: (i) that its bid in the New Bidding be computed at an equal to the appraisal value to be determined by an investment bank selected by ENARGAS, which represents the value of the business of providing the licensed service as it is driven by the Licensee at the valuation date, as a going concern and without regard to the debts; (ii) to obtain the new License, without payment, in the event that any bid submitted in the New Bidding exceeds the appraised value; (iii) to match the best bid submitted by third parties in the New Bidding, if it would be higher than its bid mentioned in (i), paying the difference between both values ​​ (iv) if the Company is unwilling to match the best bid made by a third party, to receive the appraisal value mentioned in (i) as compensation for the transfer of the Essential Assets to the new licensee.

ASSETS AND LIABILITIES IN FORRE

ASSETS AND LIABILITIES IN FORREIGN CURRENCY	12 Months Ended
	Dec. 31, 2018
ASSETS AND LIABILITIES IN FORREIGN CURRENCY [Abstract]
ASSETS AND LIABILITIES IN FORREIGN CURRENCY	18. ASSETS AND LIABILITIES IN FORREIGN CURRENCY The balances in foreign currency as of December 31, 2018 and 2017 are detailed below: 2018 2017 Foreign currency and amount (in thousands) Exchange rate Amount in local currency Foreign currency and amount (in thousands) Amount in local currency CURRENT ASSETS Cash and cash equivalents US$ 361,017 37.500 (1) 13,538,138 US$ 70,732 1,937,122 Other financial assets at amortized cost US$ 152 37.500 (1) 5,714 US$ 49,723 1,361,756 Other financial assets at fair value through profit or loss - - US$ 11,873 325,158 Trade receivables US$ 31,507 37.500 (1) 1,181,514 US$ 57,838 1,584,011 Other receivables US$ 1,693 37.500 (1) 63,488 US$ 2,433 66,632 14,788,854 5,274,679 NON CURRENT ASSETS Trade receivables - - US$ 165 4,511 - 4,511 TOTAL ASSETS 14,788,854 5,279,190 CURRENT LIABILITIES Trade payables US$ 42,184 37.700 (2) 1,590,337 US$ 44,882 1,238,162 Loans US$ 11,746 37.700 (2) 442,836 US$ 71,278 1,962,609 2,033,173 3,200,771 NON CURRENT LIABILITIES Loans US$ 534,595 37.700 (2) 20,154,216 US$ 169,969 4,680,011 20,154,216 4,680,011 TOTAL LIABILITIES 22,187,389 7,880,782 (1) Buy exchange rate at the end of fiscal year (2) Sell exchange rate at the end of fiscal year US$: United States of America dollars

COMMON STOCK AND DIVIDENDS

COMMON STOCK AND DIVIDENDS	12 Months Ended
	Dec. 31, 2018
COMMON STOCK AND DIVIDENDS [Abstract]
COMMON STOCK AND DIVIDENDS	19. COMMON STOCK AND DIVIDENDS a) Common stock structure and shares’ public offer As of December 31, 2018, TGS’ common stock was as follows: Amount of common stock, subscribed, issued, paid in, and authorized for public offer Common Shares Class (Face value $ 1, 1 vote) Outstanding shares Treasury Shares Common Stock Class “A” 405,192,594 - 405,192,594 Class “B” 375,701,909 13,600,780 389,302,689 Total 780,894,503 13,600,780 794,495,283 As of December 31, 2017 the Company did not have any treasury shares. TGS’s shares are traded on the BYMA and under the form of the American Depositary Receipts (“ADS”) (registered in the SEC and representing 5 shares each) on the New York Stock Exchange. b) Dividends distribution Under the powers delegated by the Shareholders’ Meeting held on April 10, 2018, the Board of Directors ordered the payment of the following cash dividends: Approval date Amount Amount per share 07/06/2018 1,125,562 1.4167 08/08/2018 1,449,300 1.8242 09/06/2018 1,754,326 2.2081 c) Acquisition of treasury shares On May 9, 2018, TGS’ Board of Directors approved a Program for the Acquisition of Shares of the Company in the Argentine peso market (the “Shares Repurchase Program”). Considering the solid cash and investment position of the Company, this program was approved due to the distortion evidenced by the Company’s economic value, measured by its current business and those derived from projects in development, and the price of the quotation of their shares in the market. Considering the realized and liquid gains that arose from the financial statements for the three-month period ended March 31, 2018, the Board determined the maximum amount to be invested in Ps. 1,700,000 stated at its original value. Subsequently, on September 6, 2018, the Board of Directors of the Company approved a second treasury shares repurchase program for a maximum amount of up to Ps. 1,800,000 stated at its original value and for a term of 180 calendar days, which expired on March 5, 2019. As of December 31, 2018, the Company held 13,600,780 treasury shares, representing 1.71% of the total common stock. The acquisition cost restated for inflation amounted to Ps. 1,420,926, which, in accordance with the provisions of Title IV, Chapter III, article 3.11.c of the rules, restricts the amount of the retained earnings that the Company may distribute.

LEGAL CLAIMS AND OTHER MATTERS

LEGAL CLAIMS AND OTHER MATTERS	12 Months Ended
	Dec. 31, 2018
LEGAL CLAIMS AND OTHER MATTERS [Abstract]
LEGAL CLAIMS AND OTHER MATTERS	20. LEGAL CLAIMS AND OTHER MATTERS a) Turnover tax calculated on the natural gas price consumed by TGS The Company has interpretative differences with several provinces regarding the liquidation of the turnover tax calculated on the natural gas used by TGS as fuel to render its transportation services. In this framework there have been initiated several lawsuits against TGS, which have adversely concluded by the Company. During fiscal year 2017 and 2016, the Company continued to receive several claims from different provinces, which meant that TGS paid Ps. 148.5 million and Ps. 27.6 million to provincial agencies (stated at their original values), respectively. On May 24, 2017, ENARGAS issued Resolution No. 5041/2017, which approved the tariff methodology for turnover tax on gas withheld from those determinations or liquidations that the Company receives as of its date of issue. As of December 31, 2018 and 2017, the Company recorded a provision of Ps. 308.4 million and Ps. 279.6 million, respectively, in respect of this contingency under the line item “Provisions.” Those amounts were determined in accordance with the estimations of tax and interests, that would be payable as of such date. b) Action for annulment of ENARGAS Resolutions No. I-1,982/11 and No. I-1,991/11 (the “Resolutions”) After the issuance of the Resolutions, TGS filed a judicial action before the National Court of First Instance in Federal Administrative Litigation No. 1 (the “Court”) in order to obtain the declaration of nullity of the Executive Decree No. 2067/08 and the Resolutions as well as the unconstitutionality of the administrative acts that created the Charge. The probative stage of these proceedings was concluded and the allegations are currently being carried out. On July 5, 2012, the Court issued in favor of TGS a precautionary measure by which the suspension of the Charge was ordered in the terms set forth in the Resolutions. This decision was appealed in different opportunities by the National Government, by virtue of which the dictating of the precautionary measure was limited to the validity of six months. However, at maturity, the Company is entitled to obtain a new precautionary measure for a similar period. As a result, on September 19, 2017, a new extension of the injunction was obtained (which prevented the Government to claim TGS of the payment of the amounts resulting from the new value of the Charge for the period between the November 2011 and March 2016), thus extending the validity until March 2018. On the other hand, the National Court of Appeals in Contentious Administrative Dismissal rejected the extraordinary appeal filed by the National Government against the judgment of that court that confirmed the rejection made by the Court at the request of ENARGAS to declare abstract the legal action initiated by TGS in accordance with the precedent “Alliance” issued by the Supreme Court in December 2014. On September 1, 2018, a new extension of the precautionary measure was granted to TGS (which prevents the National Government from claiming from TGS the payment of amounts resulting from the new value of the Charge for the period between November 2011 and March 2016), extending their validity until March 11, 2019 or until the judgment that resolves the merits of the matter, whichever occur first. On March 26, 2019, TGS was served notice that the Court upheld the legal action filed by TGS and declares the unconstitutionality of Executive Decree no. 2067/08 and the Resolutions, as well as of any other act aimed at enforcing the Decree, and therefore declares invalid said regulations. On March 29, 2019, the National Secretary of Energy appealed the judgment, which was granted on April 3, 2019. The Company´s Management believes it has sufficient valid arguments to defend its position, and thus, the Company has not recorded any liability from the charge for natural gas consumptions from the date of obtaining the injunction until April 1° 2016, and of the effective date of Resolution 28. c) Recovery action of VAT and income tax On October 9, 2008, TGS signed the 2008 Transitional Agreement with ex UNIREN that contemplated a tariff increase of 20%, applicable as from September 1, 2008. On December 3, 2009, the Executive Branch ratified this transitional agreement through the Presidential Decree No. 1,918/09. By means of this decree, TGS was able to bill the tariff increase to its clients as soon as ENARGAS would have published the new tariffs schedule and set the methodology to bill the retroactive effect. Finally, this administrative act did not become effective and therefore in September 2010 TGS filed an acción de amparo On May 24, 2013, TGS filed a tax recovery appeal with respect to the income tax and VAT credits generated by the reversal of the tariff increase credit mentioned above. The total amount claimed by TGS amounted to Ps. 69.4 million plus compensatory interests. After the omission to pass judgment on the claim within the three months of the filing of the tax recovery appeal, on October 9, 2013, TGS filed an appeal before the Federal Tax Bureau. On June 6, 2017, the Tax Court of the Nation rejected the claim for recovery filed by the Company. This resolution was appealed by TGS. The balance of the receivable as of December 31, 2016 was Ps. 105 million. Given the negative judgment, this receivable was derecognized and charged under “Other operating results, net” of the Statement of Comprehensive Income for the year ended December 31, 2017. d) Turnover tax withholding in the Province of Buenos Aires The Company was notified by ARBA regarding the initiation of various determinative procedures in which TGS is claimed for a total of Ps. 4.9 million (without fine or interest) for the omission as agent of withholding and collection of the turnover tax corresponding to the period July 2009 - June 2011. Given this determination, the Company presented to ARBA various elements of evidence that allow reducing substantially the amount claimed. As of the date of issuance of these consolidated financial statements, the Tax Court has not resolved the issue. In March 2017, TGS partially canceled the debt claimed by ARBA, paying Ps. 2.9 million (stated in its original value) through the adhesion to the payment plans offered by the Province of Buenos Aires through Law 14,890. Adherence to these payment plans allowed partial cancellation of compensatory interest and all fines and charges claimed by ARBA. As of the date of the issuance of these Consolidated Financial Statements, only two files remain in relation to the alleged failure of TGS to act as withholding and collection agent during 2009 and 2010. The Company’s Management considers that it has sufficient arguments to assert its defense so at December 31, 2018 it has no recorded any provision for this concept. e) Environmental matters The Company is subject to extensive environmental regulations in Argentina. TGS’ management believes that its current operations are in material compliance with applicable environmental requirements, as currently interpreted and enforced. The Company has not incurred in any material environmental liabilities as a result of its operations to date. f) Arbitral claim On May 8, 2015, the Secretariat of the International Court of Arbitration of the International Chamber of Commerce notified TGS regarding the request for arbitration initiated by PAE and Pan American Sur SA (the “claimants”) related to the execution of three natural gas processing contracts between the applicants and TGS (the “Agreements”). On April 4, 2016, the Company was notified of the beginning of the corresponding demand, which TGS was responded on August 17, 2016. According to the demand, the applicants allege breach of contracts during the period between February 2006 and February 2016, that would have resulted in a lower allocation of the products obtained (the “Products”), claiming U.S.$ 163 million, plus interest (the “Claim”). On March 16, 2017, the Claimants filed their Reply Memorial, whereby they replied to TGS Response Memorial and adjusted the amount of their claim to U.S. $ 306.3 million as of March 15, 2017, the total amount that would consist of U.S.$ 134.0 million in nominal damages plus U.S.$ 172.3 million of interest. To this amount, accrued interest would be added from March 15, 2017 until the date of effective payment. Subsequently, on July 14, 2017, the Company presented the Rejoinder Memorial, whereby the arguments put forward by the claimants in their Reply Memorial were answered. Between September 25 and 29, 2017, the Arbitration Testing Hearing took place in the City of Buenos Aires, in which the legal advisors of the Company understand that the evidence produced confirmed TGS ‘position regarding the main aspects of the claim. . On December 15, 2017, the Claimants and TGS submitted their Final Conclusions Memorials. On May 28, 2018, the ICC issued the final award by which it partially acknowledged the claim and ruled that the Company must pay damages to the claimants in the amount of U.S.$ 19 million, plus interest accrued as from May 8, 2015 until the date of actual payment. This payment was made on June 14, 2018 for an amount of U.S.$ 21.3 million. g) Others In addition to the matters discussed above, the Company is a party to certain lawsuits and administrative proceedings which involve taxation, labor claims, social security, administrative and others arising in the ordinary course of business. The Company’s Management and its legal advisors estimate that the outcome of these differences will not have significant adverse effects on the Company’s financial position or results of operations. As of December 31, 2018 and 2017, the total amount of these provisions amounted Ps. 59.7 million and Ps. 9.6 million, respectively.

BALANCES AND TRANSACTIONS WITH

BALANCES AND TRANSACTIONS WITH RELATED COMPANIES	12 Months Ended
	Dec. 31, 2018
BALANCES AND TRANSACTIONS WITH RELATED COMPANIES [Abstract]
BALANCES AND TRANSACTIONS WITH RELATED COMPANIES	21. BALANCES AND TRANSACTIONS WITH RELATED COMPANIES Technical, Financial and Operational Assistance Agreement Pampa Energía is TGS’s technical operator, according to the approval of ENARGAS in June 2004, and subject to the terms and conditions of the Technical Assistance Agreement which provides that Pampa Energía is in charge of providing services related to the operation and maintenance of the natural gas transportation system and related facilities and equipment, to ensure that the performance of the system is in conformity with international standards and in compliance with certain environmental standards. For these services, the Company pays a monthly fee based on a percentage of the operating income of the Company. In December 2017, after having obtained the prior approval of ENARGAS, TGS and Pampa Energía renewed the Technical Assistance Agreement for a three-year term as of December 28, 2017, due on December 28, 2020. For this service, TGS will pay Pampa Energía the higher of: (i) a fixed annual amount of U.S.$ 3.0 million or (ii) 7% of annual comprehensive profits (before financial results and income tax and after deducting also the aforementioned fixed sum) of TGS. Commercial transactions In the normal course of its activity, TGS celebrated with Pampa Energía and other companies related to it, agreements to transfer natural gas and its richness. The price, which is denominated in US dollars, is determined according to common market practices. In addition, in the normal course of business, TGS carries out liquid sales, natural gas transportation services and other services with its associated companies, Pampa Energía and related companies. Financial lease agreement with Pampa Energía As mentioned in Note 13 to these Consolidated Financial Statements, on August 11, 2016, the Company entered into a finance lease agreement with Pampa Energía (formerly Petrobras Argentina). Key management compensation The accrued amounts corresponding to the compensation of the members of the Board of Directors, the Statutory Committee and the Executive Committee for the years ended December 31, 2018, 2017 and 2016 were Ps. 83,820, Ps. 85,648 and Ps. 79,094, respectively. Acquisition of CTG On August 8, 2017, the Company acquired the entire shareholding of CTG from Pampa Energía for Ps. 148. The purpose of this company is to carry out various activities related to electric power. Balances and transactions with related parties The detail of significant outstanding balances for transactions entered into by TGS and its related parties as of December 31, 2018, 2017 and 2016 is as follows: 2018 2017 Company Accounts receivable Accounts payable Accounts receivable Accounts payable Controlling shareholder: CIESA - - 58 - Associate which exercises joint control on the controlling shareholder: - - Pampa Energía (1) 91,684 1,850,505 23,152 1,457,352 Associate which exercises significant influence on the controlling shareholder: - - Link 6,482 - 768 - EGS - - - 679 TGU - 6,001 - 4,383 Other related companies: - - Refinor S.A. - - - 5,218 SACDE 214,148 - - - Pampa Comercializadora S.A. 7,113 - 2,779 - Oleoductos del Valle S.A. 3,131 - 1,975 - Central Piedra Buena S.A. 25,463 - 7,661 - Transener S.A. 91 - 44 - Total 348,112 1,856,506 36,437 1,467,632 (1) Accounts payable includes Ps. 1,655,409 and Ps. 1,316,061 corresponding to the financial leasing recorded as “Loans” as of December 31, 2018 and 2017, respectively. Additionally, during 2018, the Company received from SACDE S.A. Construcciones engineering services for Ps 263,580 which are capitalized in the caption Work in progress. The detail of significant transactions with related parties for the years ended December 31, 2018, 2017 and 2016 is as follows: Year ended December 31, 2018: Revenues Costs Financial results Company Natural Gas Transportation Production and commercialization of liquids Other services Gas purchase and others Compensation for technical assistance Revenues for administrative services Interest expense Controlling shareholder: CIESA - - - - - 146 - Associate which exercises joint control on the controlling shareholder: Pampa Energía 439,556 1,323 230,930 617,089 1,317,176 - 125,467 Associates with significant influence: Link - - 8,589 - - - - Other related companies: Petrolera Entre Lomas S.A. (1) - - - 2,017 - - - Oleoductos del Valle S.A. 6,149 - 8,277 - - - - Pampa Comercializadora S.A. 26,869 - - - - - - Central Piedra Buena S.A. 67,175 - - - - - - Transener S.A. - - 12,014 - - - - Experta ART - - - 11,910 - - - Total 539,749 1,323 259,810 631,016 1,317,176 146 125,467 (1) Year ended December 31, 2017: Revenues Costs Financial results Company Natural Gas Transportation Production and commercialization of liquids Other services Gas purchase and others Compensation for technical assistance Revenues for administrative services Interest expense Controlling shareholder: CIESA - - - - - 154 - Associate which exercises joint control on the controlling shareholder: Pampa Energía 44,683 93,573 116,186 227,044 577,187 - 107,731 Jointly control entity: UT - - - - - 2,115 - Associates with significant influence: Link - - 7,486 - - - - Other related companies: Oleoductos del Valle S.A. 7,460 - 1,700 - - - - Refinor S.A. - - - 5,350 - - - Petrolera Pampa S.A. - - - 40,344 - - - Petrolera Entre Lomas S.A. - - - 17,801 - - - Pampa Comercializadora S.A. 10,775 - - - - - - Central Piedra Buena S.A. 13,160 - - - - - - Central Térmica Loma La Lata S.A. - - 389 - - - - Experta ART - - - 11,949 - - - Total 76,078 93,573 125,761 302,488 577,187 2,269 107,731 Year ended December 31, 2016: Revenues Costs Financial results Company Natural Gas Transportation Production and commercialization of liquids Other services Gas purchase and others Compensation for technical assistance Revenues for administrative services Interest expense Controlling shareholder: CIESA - - - - - 244 - Associate which exercises joint control on the controlling shareholder: Pampa Energía 43,034 2,317 354,464 163,345 329,826 - 50,145 Associates with significant influence: Link - - 7,787 - - - - Other related companies: Compañía Mega 3,325 176,841 35 - - - - Braskem - 42,611 - 4,361 - - - Petroleo Brasileiro - 546,476 - - - - - Petrolera Pampa S.A. - - - 333,944 - - - Oleoductos del Valle S.A. 4,715 - - - - - - Pampa Comercializadora S.A. 7,009 - - - - - - Petrouruguay 722 95 - - - - - WEB SA 220 - - 7,262 - - - Petrolera entre Lomas S.A. - - 350 50,356 - - - Central Piedrabuena S.A. 14,162 - - - - - - Experta ART - - - - - - - Total 73,187 768,340 362,636 559,268 329,826 244 50,145

CONTRACTUAL OBLIGATIONS

CONTRACTUAL OBLIGATIONS	12 Months Ended
	Dec. 31, 2018
CONTRACTUAL OBLIGATIONS [Abstract]
CONTRACTUAL OBLIGATIONS	22. CONTRACTUAL OBLIGATIONS As of December 31, 2018, the Company had the following contractual commitments: Estimated maturity date Total Due less than one year Less than one year 1-2 years 3-5 years More than 5 years Financial indebtedness (1) 27,120,439 - 1,272,376 3,817,125 2,544,750 19,486,188 Purchase obligations (2) 4,836,612 - 3,396,343 1,440,269 - - Financial Leases 2,199,572 56,892 281,995 564,068 564,050 732,567 Total 34,156,623 56,892 4,950,714 5,821,462 3,108,800 20,218,755 (1) (2) The totality of the financial indebtedness of TGS and the obligations corresponding to gas purchases are denominated in U.S. dollars which have been translated into Argentine pesos at the exchange rate as of December 31, 2018 (U.S.$ 1.00 = Ps. 37.7). The amounts to be paid in pesos could vary depending on the actual fluctuations in the exchange rate. For further information, see Note 17.a. (a) Guarantees granted and goods of restricted availability The Company has not granted any additional guarantees other than those set out in the remaining notes.

ASSOCIATES AND JOINT ARRANGEMEN

ASSOCIATES AND JOINT ARRANGEMENTS	12 Months Ended
	Dec. 31, 2018
ASSOCIATES AND JOINT ARRANGEMENTS [Abstract]
ASSOCIATES AND JOINT ARRANGEMENTS	23. ASSOCIATES AND JOINT ARRANGEMENTS Link: Link was created in February 2001, with the purpose of the operation of a natural gas transportation system, which links TGS’s natural gas transportation system with the Cruz del Sur S.A. pipeline. The connection pipeline extends from Buchanan, located in the high-pressure ring that surrounds the city of Buenos Aires, which is part of TGS’s pipeline system, to Punta Lara. TGS’s ownership interest in such company is 49% and Dinarel S.A. holds the remaining 51%. TGU: TGU is a company incorporated in Uruguay. This company rendered operation and maintenance services to Gasoducto Cruz del Sur S.A. and its contract terminated in 2010. TGS holds 49% of its common stock and Pampa Energía holds the remaining 51%. EGS (in liquidation): In September 2003, EGS, a company registered in Argentina, was incorporated. The ownership is distributed between TGS (49%) and TGU (51%). EGS operates its own pipeline, which connects TGS’s main pipeline system in the Province of Santa Cruz with a delivery point on the border with Chile. In October 2012, ENARGAS issued a resolution which authorizes EGS to transfer the connection pipeline and service offerings in operation to TGS. On December 17, 2013, the sale of all the fixed assets of EGS to TGS for an amount of U.S.$ 350,000 was made, the existing natural gas transportation contracts were transferred and the procedures to dissolve the Company were initiated. The Board of Directors Meeting held on January 13, 2016, approved to initiate the necessary steps for the dissolution of EGS. The Extraordinary Shareholders Meeting held on March 10, 2016 appointed EGS’ liquidator. On October 13, 2016, the liquidator of EGS resolved the distribution of a dividend in kind of Ps. 8,679 through the partial transfer of the credit that EGS has with TGS as a result of the sale of the Connection Gas Pipeline, which was implemented through TGS and TGU Assignment Agreements, which had full effects on November 4, 2016. UT: The Board of Directors of TGS approved the agreement to set up the UT together with SACDE. The objective of the UT is the assembly of pipes for the construction of the project of “Expansion of the System of Transportation and Distribution of Natural Gas” in the Province of Santa Fe, called by National Public Bid No. 452-0004-LPU17 by the MINEM (the “Work”). On October 27, 2017, TGS - SACDE UT signed the corresponding work contract with the MINEM. The maximum execution period was set in 365 days, counted from the signing of the certificate of commencement of the works, held on November 15, 2017. The validity of the UT will be until it has fulfilled its purpose, once the Work is completed and until the end of the guarantee period, set at 18 months from the provisional reception. As of December 31, 2018, works are in progress.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2018
SUBSEQUENT EVENTS [Abstract]
SUBSEQUENT EVENTS	24. SUBSEQUENT EVENTS The financial statements were authorized for issuance by the Board of Directors on April 25, 2019. There are no subsequent events between the closing date of the annual period and the approval (issuance) of these financial statements, other than the ones already disclosed and those mentioned below: Approval of a new stock buyback program On March 27, 2019, the Board of Directors of the Company approved a third treasury shares repurchase program for a maximum amount of up to Ps. 1,500,000 stated at its original value and for a term of 180 calendar days. As of the date of issuance of this Financial Statements, the Company held 15,310,025 treasury shares, representing 1.93% of the total common stock Annual Ordinary Shareholders’ Meeting On April 11, 2019, the Annual Ordinary Shareholders’ Meeting (the “2019 Shareholders’ Meeting” It is noteworthy that the above mentioned decisions made by the 2019 Shareholders’ Meeting were taken considering current CNV regulations (Resolution No. 777/2018) which states accumulated results have to be adjusted by inflation using the rates as of the month before the meeting was held. In case of 2019 Shareholders’ Meeting, TGS used the inflation rates as of February 28, 2019. Cash dividend payment On April 11, 2019, the Board of Directors approved a cash dividend payment of Ps. 240,500 (Ps. 0.31 per share) to be disposed of the capital expenditures, stock buyback and cash dividends reserve.

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2018
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
New accounting standards	a) New accounting standards New standards and interpretations issued by the IASB effective for the periods beginning on or after January 1, 2018 adopted by the Company Below is a description of the standards, amendments and interpretations to existing standards that have been issued and were mandatory for the Company’s fiscal years beginning on or after January 1, 2018: IFRS 15 Revenue from contracts with customers In May 2014, IFRS 15 “Revenue from contracts with customers” was issued which establishes a new model for entities to account for revenue arising from contracts with customers. IFRS 15 will supersede the current revenue recognition guidance including IAS 18 “Revenue”, IAS 11 “Construction Contracts” and the related interpretations when it becomes effective. The Company adopted IFRS 15 using the modified retrospective method of adoption with the date of initial application of January 1, 2018. Accordingly, the Company elected to apply the standard to all outstanding contracts as at January 1, 2018. Therefore, the comparative information was not restated and continues to be reported under IAS 11, IAS 18 and related Interpretations. The core principle of IFRS 15 is that an entity shall assess the goods or services promised in a contract with a customer and shall identify its performance obligations. IFRS 15 introduces a 5-step approach to recognize revenue: Step 1: Identify the contract with a customer. Step 2: Identify the performance obligations in the contract. Step 3: Determine the transaction price. Step 4: Allocate the transaction price to the performance obligations in the contract. Step 5: Recognize revenue when (or as) the entity satisfies a performance obligation. The new revenue recognition model established in IFRS 15 is applicable to all contracts with customers, except other relevant IFRS rule applies such as for lease contracts, insurance contracts and financial instruments. Further, the recognition of interest and dividends are not under the scope of this standard. According to IFRS 15, among other issues, a mechanism is established for assigning the transaction price among the different performance obligations. According to this standard, the Company must recognize its income once the performance obligations are satisfied; this is whenever the “control” over the goods or services is transferred to the client. The standard specifies the accounting for the incremental cost of obtaining a contract with a customer and for the cost incurred to fulfill a contract with a customer. Note 8.i includes the main revenue streams of the Company. Given the analysis carried out by management, the Company has concluded that revenue recognition practices, in accordance with IAS 18, IAS 11 and related interpretations effective as of December 31, 2017, are consistent with IFRS 15 practices. Accordingly, the Company did not recognize any initial impact in its accumulated retained earnings as of January 1, 2018. The Company has made certain reclassifications on the statement of financial position in order to reflect classification and terminology used by IFRS 15. They correspond to the contract liabilities in relation to the advances from customers as prepayments for services to be rendered, which were previously presented as “Advances from Customers” line items (Ps. 1,751,960 as of January 1, 2018). The following table shows the impact in the Statement of Financial Position as January 1, 2018: Balances as of 31/12/2017 IFRS 15 impact Balances as of 01/01/2018 Current liabilities Advances from customers 216,820 (216,820) - Contract liabilities - 216,820 216,820 Total 216,820 - 216,820 Non current liabilities Advances from customers 1,535,140 (1,535,140) - Contract liabilities - 1,535,140 1,535,140 Total 1,535,140 - 1,535,140 The application of IFRS 15 has not had an impact on the accounting policies of the Company regarding the recognition of revenues of the different business segment. IFRS 9 Financial instruments IFRS 9 introduces new requirements to the classification and measurement of financial instruments, impairment and hedge accounting. IFRS 9 replaces, as from January 1, 2018, IAS 39 Financial Instruments: Recognition and Measurement, bringing together the three aspects of the accounting of financial instruments: classification and measurement; impairment; and hedge accounting. Given the analysis carried out by management, the Company did not record any adjustments to the accumulated earnings as of January 1, 2018, since the Company’s practices as of January 1, 2018 were consistent with IFRS 9. The Company made use of the exemption that allows it not to restate the comparative information of prior periods in relation to changes in classification and measurement (including impairment). As a result, the Company did not apply the requirements of IFRS 9 to the comparative periods presented. Thus, the comparative information as of December 31, 2017 and 2016 was not modified. a) Classification and measurement of financial assets and financial liabilities IFRS 9 largely retains the existing requirements in IAS 39 for the classification and measurement of financial liabilities. IFRS 9 introduces a new classification approach for financial assets, based on two concepts: the characteristics of the contractual cash flows of the financial asset and the company’s business model. The table below shows a comparison of the measurement criteria used for financial assets according to IAS 39, in contrast to the criteria used since the adoption of IFRS 9: Financial instrument Classification under IAS 39 Classification under IFRS 9 Cash and banks Loans and other receivables Amortized cost Mutual funds Fair value through profit or loss Fair value through profit or loss Bank accounts Loans and other receivables Amortized cost Government bonds (BONAR 2020) Fair value through profit or loss Fair value through profit or loss Private bonds Fair value through profit or loss Fair value through profit or loss Government bonds (LETES) Held to maturity Amortized cost Government bonds (Central Bank Notes) Held to maturity Amortized cost VRD bonds Loans and other receivables Amortized cost Trade receivables Loans and other receivables Amortized cost Other receivables Loans and other receivables Amortized cost b) Impairment of financial assets IFRS 9 replaces the ‘incurred loss’ model in IAS 39 with an “expected credit loss” (ECL) model. This requires considerable judgment to be applied with respect to how changes in economic factors affect ECL, which are determined on a weighted average basis. For further information, see “Note 4.e. – Financial Instruments and 4.h. Trade receivables and other receivables”. Given the nature of the clients with which TGS operates and its history of uncollectibility, the Company did not identify that the change in approach to the impairment method in accordance with that required by IFRS 9 results in the recognition of any adjustment to the balances at January 1, 2018 or 2018 transactions. In addition, in the case of financial investments and in accordance with current investment policies, the Company monitors the credit rating and the credit risk that these instruments have. Based on the analysis made, the Company did not identify that any adjustment should be made to the balances as of January 1, 2018 of said instruments. IFRIC 22 “Foreign Currency Transactions and Advance Consideration” This interpretation refers to the determination of the “transaction date” that determines the exchange rate to be used in the initial recognition of an asset, expense or income related to an entity that received or paid a foreign currency advance. Applies to foreign currency transactions when an entity recognizes a non-monetary asset or non-monetary liability arising from the receipt or payment of advance consideration before the entity recognizes the related asset, expense or income. For the purpose of determining the exchange rate to be used in the initial recognition of an asset, expense or income, the transaction date is the date on which the non-monetary asset or liability derived from the receipt or payment of the advance is recognized. The adoption of this standard has not had an impact on the financial position or on the results of the Company´s operations. Amendments to IAS 40 –Transfer of Investment Properties The amendments clarify that transfers to, or from, investment property can only be made if there has been a change in use that is supported by evidence. A change in use occurs when the property meets, or ceases to meet, the definition of investment property. A change in intention alone is not sufficient to support a transfer. The list of evidence for a change of use in the standard was re-characterised as a non-exhaustive list of examples to help illustrate the principle. The adoption of the amendment has not had an impact in the financial situation and results of operations of the Company as it has not held any investment property. New standards and interpretations issued by the IASB not yet effective for the period beginning on January 1, 2018 Below is a description of the standards, amendments and interpretations to existing standards that might impact the Company and are not mandatory for the Company’s fiscal years beginning on January 1, 2018 and which have not been early adopted by the Company: IFRS 16 “Leases” In January 2016, IFRS 16 “Leases” was issued which establishes a new model of accounting for leasing operations. This standard replaces the current guidance on the accounting for such operations in IAS 17 “Leases” and related interpretations. As a result of the modifications introduced, the accounting treatment of leases in the lessee accounting will undergo major changes. IFRS 16 eliminates the dual accounting model for lessee distinguishing between on-balance sheet finance leases and operating leases for which no recognition of future lease payments is required. Instead, a unique, in-balance model is developed that is similar to the current financial leasing model. There are certain exceptions for short-term and insignificant leases. It also requires the presentation of further disclosures. IFRS 16 is applicable for annual periods beginning after January 1, 2019. Adoption is retroactive. Given the analysis carried out by our management, it is not estimated that the application of IFRS 16 will have a significant impact on the accumulated results nor the financial position of the Company. IFRIC Interpretation 23 “Uncertainty over Income Tax Treatments” The interpretation clarifies the application of IAS 12 with regards to the effect of uncertain income tax position in tax gains (losses), tax base and unused tax losses / tax credits and tax rates. The interpretation specifically clarifies whether an entity should use judgment to determine each tax treatment independently or collectively. The decision should be based on which approach provides better predictions of the resolution of the uncertainty. An entity should assume that the relevant tax authority will review each tax treatment, or group of tax position and is fully aware of all the related information. • If the entity concludes that it is probable that a particular tax treatment is accepted, the entity has to determine taxable profit consistly with this tax treatment. • If the entity concludes that it is not probable that a particualr tax treatment is accpted, the entity has to use the most likely amount or the expected value of the tax treatment when determining taxable profit. The decision should be base on which method provides better predictions of the resolution of the uncertainty. IFRIC 23 is effective for annual periods beginning on or after January 1, 2019. Given the analysis carried out by our management, it is not estimated that the application of IFRIC 23 will have a significant impact on the accumulated results nor the financial position of the Company. Annual improvements to IFRS Standards 2015 – 2017 Cycle It includes amendments to IFRS 3 – Business combinations, IFRS 11 – Joint Arrangements, IAS 12 – Income tax and IAS 23 – Borrowing Costs. Regarding IAS 23 amendment clarifies that an entity treats as part of general borrowings any borrowing originally made to develop a qualifying asset when substantially all of the activities necessary to prepare that asset for its intended use or sale are complete. These amendments are effective for annual periods beginning on or after January 1, 2019. As they are accounting practices of the Company, no effect is expected on the financial statements. Amendments to IFRS 9 – Financial instruments The amendments introduced to IFRS 9, modify the application guide in relation to the classification of financial assets in the case of contractual terms that change the calendar or amount of contractual cash flows to determine whether the cash flows that could arise due to that condition are only payments of the principal and interests. When it is a condition that allows the issuer to pay (or allow the holder to repay) a debt instrument before maturity, it must be considered whether the anticipated amount represents the unpaid amount of principal and interest, and may include reasonable compensation for cancellation anticipated of the contract regardless of the event that causes the anticipated termination. These amendments are effective for annual periods beginning on or after January 1, 2019. As they are accounting practices of the Company, no effect is expected on its financial statements. Amendments to IAS 1 and IAS 8 regarding the definition of materiality In October 2018 the IASB included certain amendments to IAS 1 “Presentation of financial statements” and IAS 8 “Accounting policies, changes in accounting estimates and errors” with the objective of clarifying the concept of materiality and aligning that definition with the amendments introduced in the Conceptual Framework. Additionally, these amendments incorporate new concepts that helped both financial statement preparers and their users to prepare and interpret the financial information included in them. These amendments are applied on prospective basis and are effective for annual periods beginning on or after January 1, 2020. Early adoption is permitted. b) Consolidation
Consolidation	Subsidiary Subsidiaries are all entities over which the Company has control. The Company controls an entity when the Company is exposed to, or has rights to, variable returns from its involvement and has the ability to affect those returns through its power over the entity. Subsidiaries are fully consolidated from the date on which control is transferred to the group. They are deconsolidated from the date that control ceases. For this purpose and unless there are specific requirements, it is generally considered that TGS has control, when it has a participation equal to or greater than 50% of the available voting rights. The accounting policies of the subsidiaries are consistent with the accounting policies adopted by the Company. Inter-company transactions, balances and gain/losses from transactions between group companies are eliminated. Unrealized gain/losses are also eliminated. Detailed data reflecting subsidiary control as of December 31, 2018 and 2017 is as follows: % of shareholding Company and votes Country Closing date Main activity TGU 99.98 Argentina December 31 Telecommunication Services CTG (1) 100.00 Argentina December 31 Electricity related services (1) 100% of the shares of this company were acquired on August 8, 2017. At present, it is in the process of being transformed into S.A.U. For consolidation purposes for the year ended December 31, 2018 and 2017, the financial statements of Telcosur have been used at those dates. The subsidiary CTG does not record operations or significant assets and liabilities as of December 31, 2018 and 2017. Associates Associates are entities over which the group has significant influence but not control, generally accompanying a shareholding of between 20% and 50% of the voting rights. Investments in associates are accounted for using the equity method of accounting. Under the equity method, the investment is initially recognized at cost, and the carrying amount is increased or decreased to recognize the investor’s share of the profit or loss of the investee after the date of acquisition. The Company accounted for the investments in its associates, under the equity method on the basis on the financial statements as of September 30, 2018 of Gas Link S.A Transporte y Servicios de Gas en Uruguay SA Emprendimientos de Gas del Sur S.A. Associates with negative equity are disclosed under “Other liabilities” to the extent that the Company has incurred legal or constructive obligations, or made payments on behalf of the associate, as of the date of the financial statements. Unrealized gains and losses resulting from transactions between TGS and the associate or joint venture are eliminated to the extent of the interest in the associate or joint venture. In the table below, associates are disclosed, together with the percentage of shareholding and voting as of December 31, 2018 and 2017: % of Shareholding Company and voting Country Main activity Closing date TGU 49.00 Uruguay Pipeline maintenance December 31 EGS (“in liquidation”) 49.00 Argentina Pipeline exploitation and construction December 31 Link 49.00 Argentina Pipeline exploitation and construction December 31 Joint arrangement As indicated in “Note 23 – Associates and Joint Arrangement”, on August 7, 2017, the Company proceeded to create a UT (similar to a joint operation) with SACDE Sociedad Argentina de Construcción y Desarrollo Estratégico S.A. The Company has defined that the UT constitutes a joint operation given that it grants its participants a percentage of the rights over the assets and liabilities arising from each contract. Accordingly, the Company recognizes its share in the jointly operated assets, liabilities, revenues, costs and expenses. Accounting policies applicable to the UT have been modified and adapted, if applicable, to ensure consistency with the policies adopted by the Company. For further information regarding the UT, see Note 23.
Foreign currency translation	c) Foreign currency translation Functional and presentation currency The consolidated financial statements are presented in thousands of Argentine Pesos, which is the Company’s functional currency. Each subsidiary or associate determines its own functional currency based on the currency of the primary economic environment in which these entities operate. Transactions and balances Foreign currency transactions are translated into the functional currency using the exchange rates prevailing at the dates of the transactions or valuation where items are remeasured. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at year-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized in the profit or loss for the year. Foreign exchange gains and losses are presented in the statement of comprehensive income within financial income and financial expenses, as appropriate. Associates The functional currency of the associate company located abroad, TGU, is the US dollar, because it is the currency in which it substantially generates its income and incur its expenses. Assets and liabilities were converted into Argentine pesos using the exchange rate prevailing at the end of each year, their common stock and retained earnings at their historical exchange rates and results at average exchange rates.
Restatement to constant currency - Comparative Information	d) Restatement to constant currency - Comparative Information Regulatory framework The consolidated financial statements as of December 31, 2018, including comparative figures, have been restated to take into account changes in the general purchasing power of the Company’s functional currency (the Argentine peso) in accordance with IAS 29 “Financial Reporting in hyperinflationary economies “(“IAS 29”) and CNV General Resolution No. 777/2018. As a result, the financial statements are stated in terms of the current unit of measurement at the 2018 balance sheet date. IAS 29 requires that the financial statements of an entity that reports in the currency of a hyperinflationary economy, regardless of whether they are based on the historical cost method or the current cost method, are expressed in terms of the current unit of measurement at the closing date of the reporting period. In order to conclude on the existence of a hyperinflationary economy, the standard details a series of factors to be considered, among which is a cumulative inflation rate over three years that approaches or exceeds 100%. During the year 2017, the cumulative inflation rate over three years remained in Argentina in decreasing values ​​with respect to 2016 and below the accumulated 100% in three years. However, this trend has reversed during the first half of 2018 due to factors such as the devaluation of the exchange rate with its effect on the price of imported inputs, the continuity of the process of adjusting public service tariffs, as well as an unfavorable international context in financial issues. In this scenario, accumulated three-year inflation, measured both on the basis of wholesale price indexes and consumer price indexes, is currently above 100%, and the available projections indicate that this trend will not be reversed in the short-term. In order to evaluate the aforementioned quantitative condition, and also to restate the financial statements, the CNV has established that the series of indexes to be used for the application of IAS 29 is determined by the FACPCE. This series of indexes combines the National Consumer Price Index (“CPI”) as of January 2017 (base month: December 2016) with the Domestic Wholesale Price Index (“WPI”), both published by the Institute National Statistics and Census (“INDEC”) until that date. For the months of November and December 2015, for which there is no information from the INDEC on the evolution of the WPI, the variation in the CPI of the Autonomous City of Buenos Aires was applied. Considering the aforementioned index, inflation was 47.64%, 24.79% and 34.59% in the years ended December 31, 2018, 2017 and 2016 respectively. Restatement mechanism The financial statements must be adjusted to consider changes in the general purchasing power of the currency, so that they are expressed in the current unit of measurement at the end of the reporting period. Said requirements also include all the comparative information of the financial statements, without modifying the decisions made based on the financial information corresponding to those financial years. Restatement of the balance sheet i. Monetary items (those with a fixed nominal value in local currency) are not restated, since they are already expressed in the current unit of measurement at the closing date of the reporting period. In an inflationary period, maintaining monetary assets generates loss of purchasing power and maintaining monetary liabilities generates a gain in purchasing power, provided that such items are not subject to an adjustment mechanism that compensates to some extent for these effects. The monetary loss or gain is included in the result of the period in which it is reported. ii. The non-monetary items measured at their current values ​​at the end of the reporting period are not restated for the purpose of their presentation in the balance sheet, but the adjustment process must be completed to determine in terms of a homogeneous unit of measurement the results produced by the holding of these non-monetary items. iii. Non-monetary items measured at historical cost or at a fair value as of a date prior to the closing date of the reporting period are restated by coefficients that reflect the variation in the general price level from the date of acquisition or revaluation to the closing date, proceeding then to compare the restated amounts of those assets with the corresponding recoverable values. iv. The restatement of non-monetary assets in the terms of the current unit of measurement at the end of the reporting period without an equivalent adjustment for tax purposes, results in a temporary taxable difference and the recognition of a deferred tax liability whose counterparty is recognized in the result of the period. For the closing of the subsequent period, the deferred tax items are restated for inflation to re-determine the charge to the result of the next period. v. When the capitalization of costs for loans in non-monetary assets in accordance with IAS 23 is applicable, the portion of those costs that compensate the lender for the effects of inflation is not capitalized. For the years ended December 31, 2018 and 2017 the Company did not capitalize financial costs. Restatement of the Comprehensive Income Statement Revenues and expenses (including interest and foreign exchange differences) are restated from the date of their booking, except for those items of the result that reflect or include in their determination the consumption of assets measured in purchasing power of a date before the consumption booked, which are restated based on the date of origin of the asset to which the item is related (for example, depreciation and other consumption of assets valued at historical cost); and also those results that arise from comparing two measurements expressed in purchasing power currency of different dates, for which it is necessary to identify the amounts compared, restate them separately, and make the comparison, but with the amounts already restated. The result of the exposure to the change in the purchasing power of the currency (monetary results) is presented in a separate line and reflects the effect of inflation on the monetary items. Restatement of the statement of changes in equity As of the transition date (January 1, 2016), the Company applied the following special rules: i. The components of the capital stock were restated from the dates they were contributed. ii. Reserved earnings were maintained at the date of transition at their nominal value (legal amount without restatement). iii. The restated unallocated results were determined by the difference between the net assets restated at the transition date and the rest of the initial equity components expressed as indicated in the preceding sections. iv. After the restatement at the transition date, all the components of the equity are restated by applying the general price index from the beginning of the period, and each variation of those components is restated from the date of contribution or from the moment in which is added by any other means. Restatement of the statement of cash flows IAS 29 requires that all items in this statement should be restated in terms of the current unit of measurement as of the closing date of the period for which it is reported. The monetary result generated by cash and cash equivalents is presented in the statement of cash flows separately from cash flows from operating, investing and financing activities, as a specific item of the reconciliation between cash and cash equivalents at the beginning and at the end of the year. The effects of adopting IAS 29 on equity at the transition date and as of December 31, 2017 and 2018 and the results for the year 2016 and 2017 are as follows: Balances as of 01/01/2016 Balances as of 12/31/2016 Balances as of 12/31/2017 Total equity according to financial statements approved on 04/13/2018 1,695,434 2,526,378 5,319,640 Increase due to adjustment of common stock 17,321,734 17,321,734 17,321,734 (Decrease) / increase in accumulated retained earnings (368,161 ) (319,709 ) 2,638,215 Total equity after the application of IAS 29 18,649,007 19,528,403 25,279,589 2016 2017 Total comprehensive income for the year ended December 31, 2016 and 2017 according to financial statements approved on 04/13/2018 930,678 2,793,266 Gain on net monetary position 1,038,647 465,975 Restatement of income / (expense) items including income tax (863,030 ) 2,491,952 Total comprehensive income after the application of IAS 29 1,106,295 5,751,193
Financial instruments	e) Financial instruments Financial assets Recognition and initial measurement As of January 1, 2018, financial assets are classified, at the time of initial recognition, as: i. Financial assets subsequently measured at amortized cost, and ii. Financial assets subsequently measured at fair value (either with changes in other comprehensive income or with changes in results). The classification of financial assets at initial recognition depends on the financial asset’s contractual cash flow characteristics and the Company’s business model for managing them. For additional information, see Note 16.2.1. Financial assets are initially measured at fair value, net of transaction costs except for those financial assets classified at fair value through profit or loss. Financial assets at fair value through profit or loss are initially recognized at their fair value while transaction costs are expensed. Subsequent measurement After initial recognition, financial assets are measured according to their initial classification according to the following categories: Financial assets at amortized cost It is the most relevant category used by the Company, financial assets are classified and measure at amortized cost if both of the following conditions are met: • The financial asset is held within a business model with the objective to hold financial assets in order to collect contractual cash flows; and • The contractual terms of the financial asset give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. Financial assets at amortized cost are subsequently measured using the effective interest method. Gains and losses are recognized in the Statement of Comprehensive Income under financial results when the asset is derecognized, modified or impaired. Financial assets at fair value through OCI (Debt instruments) Corresponds to financial assets that are maintained in a business model whose objective is achieved by obtaining contractual cash flows and selling them. Unrealized gains or losses arising from changes in fair value are recognized as other comprehensive income, except for the accrual of interest, exchange rate difference and the impairment of such assets that are recognized as financial results in the Statement of Comprehensive Income. At the time the asset is written off, the accumulated gain or loss is recognized as a financial result and it is eliminated from the respective reserve. Financial assets designated at fair value through OCI (equity instruments) Upon initial recognition, the Company can elect to classify irrevocably its equity investments as equity instruments designated at fair value through OCI when they meet the definition of equity under IAS 32. Gains and losses on these financial assets are never recycled to profit or loss. Dividends are recognized as other income in the Statement of Comprehensive Income when the right of payment has been established, except when the Company benefits from such proceeds as a recovery of part of the cost of the financial asset, in which case, such gains are recorded in OCI. Equity instruments designated at fair value through OCI are not subject to impairment assessment. Financial assets at fair value through profit or loss In the event that financial assets are not classified according to the aforementioned categories, they will be subsequently measured at fair value, presenting gains or losses arising from changes in fair value in the income statement within financial results in the year in which they are originated. Impairment of financial assets The Company applies the PE model for those financial assets accounted for at amortized cost or at fair value through OCI. The PE is based on the difference between the contractual cash flows due in accordance with the contract and the cash flows that the Company expects to receive, discounted at an approximation of the original effective interest rate. To this end, the Company evaluates various factors, including credit risk, historical trends and other available information. The application of this model implies recognition of: • Expected credit losses within of 12 months: these are expected credit losses that result from possible default events within 12 months after the filing date; and • Expected credit losses during the life of the asset: these are expected credit losses that result from possible events of default during the expected life of a financial instrument. In case a loss allowance is recognized, the carrying amount of the asset is reduced through an impairment account and the amount of the loss is presented in the Statement of Comprehensive Income at the time it occurs. Subsequent recoveries of amounts previously written off are credited in the same line item. The impairment tests performed on accounts receivable are described in Note 4.h. Accounting policies applied to financial assets until December 31, 2017 The Company has applied IFRS 9 retrospectively, but has elected not to restate comparative information. As a result, the comparative information provided continues to be accounted for in accordance with NIC 39. Until December 31, 2017, financial assets were classified as follows: 1. Financial assets at fair value through profit or loss 2. Financial assets held to maturity 3. Loans and other receivables 4. Financial assets available for sale Financial liabilities Includes trade payables, loans, other payables and certain payroll and social security taxes payable. Recognition and initial measurement Financial liabilities are classified, at initial recognition, as subsequently measured at amortized cost or at fair value through profit or loss, as appropriate. All financial liabilities are recognized initially at fair value and, in case of measured at amortized cost, net of transaction costs. Subsequent measurement Financial liabilities at fair value through profit or loss Includes financial liabilities held for trading. As of December 31, 2018 and 2017, there are no instruments classified in this category. Other financial liabilities The Company includes financial liabilities with fixed or determinable payments that are not quoted in an active market. Current liabilities are included, except those whose maturity exceeds twelve months, which are included as non-current liabilities. They are measured using the effective interest method. As of December 31, 2018 and 2017, all of the Company’s financial liabilities were classified in this category. Offsetting of financial instruments Financial assets and liabilities are offset when there is a legally enforceable right to offset the recognized amounts and there is an intention to settle on a net basis, or realize the asset and settle the liability simultaneously.
Derivative financial instruments	f) Derivative financial instruments Derivative financial instruments are recognized at their fair value at inception and subsequently measured at their fair value and disclosed as assets or liabilities depending if it is gain or loss. The results of derivative financial instruments are classified under “Financial gain / expenses” in the statement of comprehensive income, or in the other comprehensive income if hedge accounting is applied. Derivative financial instruments are measured in accordance with IFRS 13 “Fair value measurement”. The method of recognizing the resulting gain or loss depends on whether the derivative is designated as a hedging instrument or not and, according to the nature of the item being hedged. As of December 31, 2018, the Company maintained derivative financial instruments that are mentioned in Note 16.1.3 to these consolidated financial statements for which the application of hedge accounting has not been opted for as defined by IFRS 9.
Inventories	g) Inventories Inventories consist of natural gas (in excess of the “Line Pack” classified as property, plant and equipment in the Company’s pipeline system, and the liquids stored obtained from natural gas processing at the Cerri Complex. Inventories are measured at the lower of cost restated for the inflation effects as mentioned in Note 4.d. or net realizable value. Cost is determined using the weighted average cost method. The cost of inventories includes expenditure incurred in purchasing and production and other necessary costs to bring them to their existing location and condition. The net realizable value is the estimated selling price in the ordinary course of business less the estimated cost of completion and the estimated costs to make the sale. The assessment of the recoverable value of these assets is made at each reporting date, and the resulting loss is recognized in the statement of comprehensive income when the inventories are overstated.
Trade receivables and other receivables	h) Trade receivables and other receivables Trade receivables are amounts due from customers for goods and services performed in the ordinary course of business. Contract assets are unbilled amounts due to customers related to works in progress. Trade receivables, contract assets and other receivables are recognized initially at fair value and subsequently measured at amortized cost using the effective interest method, less allowance for trade receivables. The tax credits (for income tax and value added tax) booked as a consequence of the tariff increase reversal (Note 20.c.) were written off as of December 31, 2017. The Company applies the simplified approach to measuring expected credit losses for trade receivables, contract assets and other receivables. For this purpose, customers have been grouped based on shared credit risk characteristics, the existence of guarantees, historical credit losses experienced and the existence of judicial proceedings aimed at obtaining payment. Once each group was defined, an expected uncollectibility rate calculated based on historic default rates adjusted to future economic conditions was assigned. Impairment losses on trade receivables and contract assets are presented as net impairment losses within operating profit. Subsequent recoveries of amounts previously written off are credited against the same line item.
Cash and cash equivalents	i) Cash and cash equivalents Cash and cash equivalents includes cash in hand, deposits with banking institutions and other short-term, highly liquid investments with original maturities not exceeding three months and without being subject to a risk of a significant change of value.
Property, plant and equipment ("PPE")	j) Property, plant and equipment (“PPE”) - Assets transferred from the privatization of GdE: - Line pack - Other items of PPE PPE additions are recorded at acquisition or construction cost less accumulated depreciation and impairment losses (if applicable), except land, which is recorded at historical cost acquisition minus any impairment (if applicable), all this restated for the effects of inflation as mentioned in Note 4.d. The cost includes the cost of replacing significant components and the borrowing costs derived from loans that finance its construction to the extent that the requirements for recognition as assets are met. Subsequent costs restated for the effects of inflation as mentioned in Note 4.d. are included in the carrying amount of the asset or recognized as a separate asset, as appropriate, only when it is probable that future economic benefits associated with the item will flow to the Company and the cost of the item can be reliably measured. The carrying amount of a replaced component is written off. In the same way, when a major maintenance is carried out, they are added to the cost of the good if the recognition criteria are satisfied, eliminating any remaining non-depreciated remaining value restated for the effects of inflation as mentioned in Note 4.d, if any, of previous overhaul. In this sense, Resolutions No. 1660/2000 (“Resolution 1660”) and No. 1903/2000 (“Resolution 1903”) issued by ENARGAS include definitions about the costs that should be considered as improvements or maintenance expenses. All other repairs and maintenance are charged to the statement of comprehensive income when incurred. In accordance with IAS 23, the Company capitalizes financial expense on long term construction projects, until the moment in which the asset is in conditions for its use. Capitalization of borrowing costs is carried out considering the provisions of IAS 29, recording as an expense in the Statement of Comprehensive Income the part of the borrowing costs that compensates for inflation during the same period. For the years ended December 31, 2018 and 2017, the Company has not capitalized any borrowing costs. Depreciation related to natural gas transportation assets is computed under the straight-line method over the estimated useful lives of the specific assets, which are not exceeding the maximum useful lives established by ENARGAS through Resolutions 1660 and 1903. For depreciation of all other PPE, the Company uses the straight-line method of depreciation based on the useful life assigned to each item. Major maintenance costs are depreciated according to the estimated time until the next major maintenance planned. Regarding the capitalized financial costs, they are depreciated based on the remaining useful lives of those components of PPE that originated such capitalization. The assets’ residual values and useful lives are reviewed, and adjusted if appropriate, at each reporting date. For further information, see Note 12. The result generated by the disposal of PPE components is recognized in the year in which it is generated. - Impairment of non-financial assets If any indication exists, the Company estimates the asset´s recoverable amount. An asset´s recoverable amount is the higher of the fair value less costs to sell that asset, and its value-in-use. That amount is determined for and individual asset, unless the asset does not generate cash inflows that are largely independent of those from other assets or groups of asset; in which case, the cash flows of the group of assets that form part of the cash-generating unit (“CGU”) to which the belong are taken. Where the carrying amount of an individual asset or CGU exceeds its recoverable amount, the individual asset or CGU, as the case may be, is considered impaired and is written down to its recoverable amount. Impairment losses are recognized in the consolidated statement of comprehensive income. Where the carrying amount of an individual asset or CGU exceeds its recoverable amount, the individual asset or CGU, as the case may be, is considered impaired and is written down to its recoverable amount. Impairment losses are recognized in the consolidated statement of comprehensive income. In assessing value in use, the estimated future cash flows are discounted to their present value using a pre-tax discount rate that reflects current market assessments of the time value of money and the risks specific to the asset for which the estimates of future cash flows have not been adjusted. To such end, the Company makes estimates and assumptions of the economic conditions that will prevail throughout the useful life of the assets. As a result of the factors mentioned above, actual cash flows and values could vary significantly from projected cash flows and the values derived from the discounting techniques used. Impairment losses, if any, are recognized in the statement of comprehensive income. As of December 31, 2018 and 2017, the carrying value of PPE does not exceed their recoverable value. Infrastructure used in the natural gas transportation service Considering the current terms and conditions of the License, TGS concluded that the License is outside the scope of IFRIC 12, as it is considered in substance to provide for an indefinite term because the infrastructure will never revert to the grantor and due to the characteristics of renewal of the License that give a similar result to what which would result from having obtained a perpetual right to operate the infrastructure. The evaluation carried out and the conclusions reached by TGS are consistent with those of other transportation and natural gas distribution companies in Argentina that are subject to the similar regulations and license agreements. The evaluation was carried out jointly, when the transportation and distribution companies adopted the IFRS in Argentina in 2012, together with the FACPCE, the Buenos Aires Stock Exchange ( Bolsas y Mercados Argentinos
Financial leases	k) Financial leases TGS classifies as financial leases when it assumes substantially all the risks and benefits of ownership of leased assets. To that end, an asset and a liability are initially recognized at the same amount as the lower value that results from comparing the fair value of the leased asset and the present value of the minimum lease payments. Subsequently, each finance lease payment should be apportioned between the finance charge and the reduction of the outstanding liability (the finance charge to be allocated so as to produce a constant periodic rate of interest on the remaining balance of the liability). The corresponding lease payments, net of financial charges, are included in “Financial leases” in the current and non-current loans caption of the Statement of Financial Position. Interest on the financial cost is charged to the Statement of Comprehensive Income in the period of the lease in order to obtain a constant periodic interest rate on the debt pending amortization in each period. Assets acquired through finance leases are restated for the effects of inflation as mentioned in Note 4.d. and are depreciated over the useful life of the assets received in accordance with current depreciation policies.
Loans	l) Loans Loans have been initially recorded at fair value net of direct attributable transaction costs. Subsequently, loans are valued at their amortized cost. Liabilities are disclosed as non-current when their maturity exceeds twelve months.
Trade payables	m) Trade payables Trade payable are initially recognized at fair value. Subsequently they are measured at amortized cost using the effective tax method.
Income tax and deferred income tax	n) Income tax and deferred income tax Income tax Income tax includes current tax and deferred income tax. Income tax is presented in the Statement of Comprehensive Income. The current income tax is calculated on the basis of tax regulations in force at each reporting period. Management periodically evaluates positions taken in tax returns with respect to situations in which tax regulations are subject to interpretation and establishes provisions if applicable. As of December 31, 2018 and 2017, there are no provisions booked for this concept. The Company has calculated income tax charges using the deferred tax method, which considers the effect of temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred income tax assets and liabilities are measured at undiscounted nominal value at the tax rates that are expected to apply in the year when the asset is realized or the liability is settled, based on tax rates and tax laws that have been enacted or substantively enacted at the reporting period rate (See note 14). A deferred tax is recognized on the temporary differences arising from investments in subsidiaries and associates, except for deferred tax liabilities where the Company is able to control the timing of the reversal of the temporary difference and it is probable that the reversal will not occur in the foreseeable future. Deferred tax assets and liabilities are offset if the Company has a legally enforceable right to offset recognized amounts and when deferred tax assets and liabilities relate to income tax levied by the same tax authority on the same taxable entity or different taxable entities that intend to settle tax assets and liabilities on a net basis. Deferred tax assets are recognized to the extent that it is probable that future taxable income will be generated against which the temporary differences can be used. The assets and liabilities generated by the application of the deferred tax were valued at their nominal amount considering the restatements for inflation mentioned in Note 4.d) and are classified as non-current assets or liabilities. Tax on minimum presumed income (“TOMPI”) The TOMPI is calculated on an individual entity basis at the statutory tax rate of 1%, and is based upon the taxable assets of each Argentine entity as of the end of the year. This tax is complementary to income tax and the Company is required to pay the greater of the income tax or the TOMPI. Any excess of the TOMPI over the income tax may be carried forward and recognized as a payment on account of any excess of income tax over TOMPI occurring within the subsequent ten years. When the Company considers it is probable that the position of TOMPI is utilized as payment on account of income tax, TGS accounts for TOMPI credit as current or non-current, as appropriate, under “Other receivables” in the statement of financial position. As of December 31, 2018 and 2017, there are no provisions booked for this concept. In accordance with the provisions of article 76 of Law No. 27,260, the TOMPI has been repealed for the periods beginning as from January 1, 2019.
Provisions	o) Provisions The Company has recorded provisions related to legal actions, judicial court, claims and administrative proceedings, including interpretive questions of the current legislation and those of regulatory nature. Provisions for legal claims and/or claims by third parties (“legal claims and others”) are recorded when the Company has a present obligation as a result of a past event, it is probable that an outflow of resources will be required to settle the obligation; and the amount has been reliably estimated. Estimates are reviewed and adjusted, as the Company obtains additional information.
Revenue recognition from contract with customers	p) Revenue recognition from contract with customers Revenue is measured at the fair value of the consideration received or to be received, and represents amounts receivable for goods and/or services supplied. Revenue is recognized when the control of goods or services is transferred to he customer and the consideration is determined by an amount that reflects the consideration that the Company expects to receive. Tax on exports and turnover tax are disclosed as Selling Expenses. The following are the accounting policies of the Company for the recognition of revenue of each of the business segments defined by our management: Natural Gas Transportation Natural Gas transportation services includes: (i) firm natural gas transportation, whose revenues are recognized when the capacity is reserved and paid for regardless of actual usage by the customer, (ii) interruptible natural gas transportation and exchange and displacement services whose revenues are recognized when services are rendered and (iii) the operation and maintenance service of the assets affected by the natural gas transportation service corresponding to the expansions promoted by the National Government and whose ownership corresponds to the trusts created for such purpose whose revenues are recognized when services are rendered. The applicable rates arise from the tariff tables published by ENARGAS. Thus Company’s revenues are recognized by the amount for which it will be entitled to receive as consideration. At the end of each month, TGS recognizes its revenues from sales equivalent to the firm reserved capacity, the volumes of natural gas transported under the modalities of interruptible and exchange and displacement and by the operation and maintenance services. In return, a trade receivable is recognized which represents an unconditional right that the Company has to receive the consideration owed by the customer. On the other hand, the billing of the service is done monthly and according to the guidelines established by ENARGAS, the consideration is received within said calendar month. Liquids Production and Commercialization This business segment includes: (i) production and commercialization of liquids on our own account, and (ii) other liquid services. Domestic Market In the domestic market, TGS sells the production of propane and butane to LPG retailers in the framework of the programs created by the National Government to supply the domestic market. The sale prices are determined by the ex-Secretary of Hydrocarbon Resources (“ SHR The price of those tons of propane and butane that are not sold within the framework of the aforementioned programs is determined by the former Ministry of MINEM based on the international reference prices. Regarding ethane sales, they are made to PBB Polisur S.R.L. (“PBB”), the only customer to whom this product is sold. To estimate transaction price, the Company uses the most probable amount method. In this regard, the Company only recognizes those transactions where it is highly probable that they will not be reversed in the future. Foreign Market In the foreign market, the Company markets propane, butane and natural gasoline to international traders (“traders”) and other clients of worldwide renown, some of them through trucks. These sales are made under short-term contracts (less than one year), with the price determined as reference to international prices plus / minus a fixed amount per ton sold. There are no variable consideration components in these contracts. For both domestic and foreign market sales, TGS transfers control and recognizes revenues when the products are delivered to the customer and therefore the product has been accepted and there is no evidence of the existence of pending obligations by the Company. It is at that moment when a trade receivable is recognized given that the receipt of the consideration is unconditional and only the passage of time is the only requirement for receiving the consideration owed by the customer. Other liquids services The Liquids production and commercialization segment also comprises reception, storage and dispatch of the liquids from the facilities located in Puerto Galván. Revenues from sales are recognized when the service is effectively rendered, that is, after the dispatch to each vessel. The price is agreed by the parties being a fixed amount per ton of product dispatched, there being no variable components in them. These services are billed monthly, at which time an unconditional right to receive the consideration from the client arises. Subsidies As part of its participation in propane and butane supply programs in the local market carried out by the National Government, (for more information see “Note 17 - Regulatory Framework - b) Regulatory framework for non-regulated segments”), the Company receives from the Secretary of Energy a series of subsidies that are recognized in accordance with the provisions of IAS 20 “Accounting for government grants and disclosures of government assistance” because they correspond to economic compensations calculated as the difference between the sale prices of the products determined in accordance with the legislation in force and the reference prices calculated by the Secretary of Energy. Subsidies are recognized at fair value whenever there is reasonable security that will be received and that the product has been delivered. They are presented within the caption “Revenue from sales” of the statement of comprehensive income. Other services The services included in the Other Services segment consist mainly of the treatment, removal of impurities and natural gas compression, as well as inspection and maintenance of pipelines and compressor plants and services of steam generation for electricity production and management services for expansion works and steam generation for the production of electricity. Revenues from sales of this business segment are recognized in the period in which the service is provided. The sale price is determined according to what arises from the contractual conditions agreed between TGS and its customers. In all cases, the recognition and billing of sales income is made on a monthly basis so that at that time a sales credit is recorded. Revenue from the Company’s participation in the joint operation with SACDE which correspond to the construction activities provided by it, are recognized based on the physical progress of the work. To calculate the costs associated with such income, the UT adopts the criterion of applying the estimated final margin for the work to the accrued revenue in each period. The costs incurred in excess of the costs associated with the revenues are recognized in the Contract assets item. Telecommunications Revenues from the provision of Telecommunications services are recognized in the statement of comprehensive income at the time of effective performance of the service. The sale price is determined according to what arises from the contractual conditions agreed between TGS and its customers. The consideration is determined as a fixed monthly amount. In all cases, the recognition and billing of sales income is made on a monthly basis so that at that time a sales receivable is recorded. Financial components The Company does not have any contracts where the period between the transfer of the promised goods or services to the customer and payment by the customer exceeds one year. As a consequence, the Company does not adjust any of the transaction prices for the time value of money.
Contract liabilities (until December 31, 2017 Advances from customers)	q) Contract liabilities (until December 31, 2017 Advances from customers) Mainly consist of pre-payments for services made by customers in order to finance the works to render the service . Additionally, it includes the advance received by the UT from the Argentine Government as payment on account of the gas pipeline construction project. For more information, see “Note 23 - Associates and joint arrangements.”
Equity accounts	r) Equity accounts The activity in the Equity accounts reflects resolutions adopted by Shareholders in their meetings, or the effects of the laws or regulations in force. The equity accounts are restated for the inflation effects according to what is mentioned in Note 4.d, except the account Capital stock which is maintained at its original value. Common stock and adjustment to common stock The common stock consists of contributions made by shareholders represented by shares and comprises outstanding shares at their face value, net of treasury shares mentioned below. Common stock accounts were restated in constant currency as mentioned in Note 4.d. Common stock account was kept at original value and the adjustment arising from such restatement is shown under “Inflation Adjustment to common stock.” Common stock adjustment is not distributable in cash or in kind but may be capitalized through issuance of shares. In addition, this balance may be used to compensate accumulated losses. Treasury shares and adjustments to treasury shares Corresponds to the reclassification of the nominal value and corresponding restatement in constant peso (Inflation Adjustment to Common Stock) of shares issued and repurchased by the Company in market transactions, as required by the current regulations of the CNV. Own equity instruments that are reacquired (treasury shares) are recognized at cost restated for the inflation effects as mentioned in Note 4.d., and deducted from equity. No gain or loss is recognized on the purchase, sale or cancellation of the Company’s treasury shares. Any difference between the carrying amount and the consideration, if reissued, is recognized as a premium on common stock. Legal Reserve Pursuant to the provisions of the Argentine Business Association Law and the CNV, the Company is required to set up a legal reserve by providing at least 5% of the aggregate amount of net income for the year, prior year adjustments, transfers of other comprehensive income to retained earnings and accumulated losses of prior years, when this aggregate amount exceeds zero until the legal reserve equals 20% of the sum of Capital stock and Adjustment to capital stock balances. Distribution of dividends The cash dividend is recognized as a liability in the Company’s financial statements in the year in which they are approved by the shareholders of the Company or the Board of Directors Retained earnings The outstanding balance of retained earnings includes accumulated gains or losses which were not allocated to a specific purpose reserve and, when positive, may be distributed pursuant to the decision of the Shareholders provided these retained earnings are not subject to legal restrictions, as mentioned above “Legal reserve”.
Basic and diluted earnings per share	s) Basic and diluted earnings per share Earnings per share as of December 31, 2018, 2017 and 2016 were calculated as follows: 2018 2017 2016 Net income attributable to owners of the Company 11,415,836 5,751,193 1,106,295 Average number of outstanding shares 788,405,563 794,495,283 794,495,283 Basic and diluted earnings per share 14.48 7.24 1.39 As of the date of the issuance of these consolidated financial statements, there are no TGS instruments outstanding that imply the existence of potential ordinary shares, thus the basic net income per share for the years ended on December 31, 2018, 2017 and 2016 matches the diluted net income per share.

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2018
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Impact of New Standards in the Statement of Financial Position	The following table shows the impact in the Statement of Financial Position as January 1, 2018: Balances as of 31/12/2017 IFRS 15 impact Balances as of 01/01/2018 Current liabilities Advances from customers 216,820 (216,820) - Contract liabilities - 216,820 216,820 Total 216,820 - 216,820 Non current liabilities Advances from customers 1,535,140 (1,535,140) - Contract liabilities - 1,535,140 1,535,140 Total 1,535,140 - 1,535,140
Comparison of Measurement Criteria Used for Financial Assets	The table below shows a comparison of the measurement criteria used for financial assets according to IAS 39, in contrast to the criteria used since the adoption of IFRS 9: Financial instrument Classification under IAS 39 Classification under IFRS 9 Cash and banks Loans and other receivables Amortized cost Mutual funds Fair value through profit or loss Fair value through profit or loss Bank accounts Loans and other receivables Amortized cost Government bonds (BONAR 2020) Fair value through profit or loss Fair value through profit or loss Private bonds Fair value through profit or loss Fair value through profit or loss Government bonds (LETES) Held to maturity Amortized cost Government bonds (Central Bank Notes) Held to maturity Amortized cost VRD bonds Loans and other receivables Amortized cost Trade receivables Loans and other receivables Amortized cost Other receivables Loans and other receivables Amortized cost
Subsidiary Control	Detailed data reflecting subsidiary control as of December 31, 2018 and 2017 is as follows: % of shareholding Company and votes Country Closing date Main activity TGU 99.98 Argentina December 31 Telecommunication Services CTG (1) 100.00 Argentina December 31 Electricity related services (1) 100% of the shares of this company were acquired on August 8, 2017. At present, it is in the process of being transformed into S.A.U.
Associates	In the table below, associates are disclosed, together with the percentage of shareholding and voting as of December 31, 2018 and 2017: % of Shareholding Company and voting Country Main activity Closing date TGU 49.00 Uruguay Pipeline maintenance December 31 EGS (“in liquidation”) 49.00 Argentina Pipeline exploitation and construction December 31 Link 49.00 Argentina Pipeline exploitation and construction December 31
Effect of New Standards Adopted	The effects of adopting IAS 29 on equity at the transition date and as of December 31, 2017 and 2018 and the results for the year 2016 and 2017 are as follows: Balances as of 01/01/2016 Balances as of 12/31/2016 Balances as of 12/31/2017 Total equity according to financial statements approved on 04/13/2018 1,695,434 2,526,378 5,319,640 Increase due to adjustment of common stock 17,321,734 17,321,734 17,321,734 (Decrease) / increase in accumulated retained earnings (368,161 ) (319,709 ) 2,638,215 Total equity after the application of IAS 29 18,649,007 19,528,403 25,279,589 2016 2017 Total comprehensive income for the year ended December 31, 2016 and 2017 according to financial statements approved on 04/13/2018 930,678 2,793,266 Gain on net monetary position 1,038,647 465,975 Restatement of income / (expense) items including income tax (863,030 ) 2,491,952 Total comprehensive income after the application of IAS 29 1,106,295 5,751,193
Earnings Per Share	Earnings per share as of December 31, 2018, 2017 and 2016 were calculated as follows: 2018 2017 2016 Net income attributable to owners of the Company 11,415,836 5,751,193 1,106,295 Average number of outstanding shares 788,405,563 794,495,283 794,495,283 Basic and diluted earnings per share 14.48 7.24 1.39

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2018
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Supplemental Cash Flow Information	Non-cash investing and financing activities for the years ended December 31, 2018, 2017 and 2016 are presented below: 2018 2017 2016 Unpaid acquisition of PPE 307,746 299,598 47,198 Principal payment of financial lease (1) 101,965 66,075 271,843 Leasing for PPE acquisition - 1,429,713 (1) Cancelled through compensation with trade receivables with the creditor. See Note 13.

CONSOLIDATED BUSINESS SEGMENT_2

CONSOLIDATED BUSINESS SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2018
CONSOLIDATED BUSINESS SEGMENT INFORMATION [Abstract]
Business Segments	Detailed information on each business segment for the years ended December 31, 2018, 2017 and 2016 is disclosed below: Year ended December 31, 2018 Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Eliminations Total Revenues 15,462,061 16,627,429 1,810,109 163,071 - 34,062,670 Intercompany revenues 598,414 - - - (598,414 ) - Cost of sales (5,164,278 ) (10,485,998 ) (1,054,245 ) (82,203 ) 598,414 (16,188,310 ) Administrative expenses (835,134 ) (84,062 ) (35,980 ) (6,637 ) - (961,813 ) Selling expenses (953,729 ) (640,173 ) (143,451 ) (27,348 ) - (1,764,701 ) Other operating expenses (156,283 ) (726,732 ) (5,445 ) (2,327 ) - (890,787 ) Operating profit 8,951,051 4,690,464 570,988 44,556 - 14,257,059 Depreciation of property, plant and equipment (1,880,377 ) (113,737 ) (228,969 ) - - (2,223,083 ) Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Total Identifiable assets 45,246,427 9,040,987 7,554,646 100,967 61,943,027 Identifiable Liabilities 16,738,045 1,496,225 12,717,432 46,020 30,997,722 Year ended December 31, 2017 Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Eliminations Total Revenues 7,456,052 11,173,975 1,199,170 124,069 - 19,953,266 Intercompany revenues 245,161 - - - (245,161 ) - Cost of sales (4,178,865 ) (7,271,556 ) (655,830 ) (74,592 ) 245,161 (11,935,682 ) Administrative expenses (597,122 ) (93,720 ) (36,475 ) (6,557 ) - (733,874 ) Selling expenses (419,570 ) (265,336 ) (106,916 ) (15,474 ) - (807,296 ) Other operating expenses (327,245 ) 64,694 (9,198 ) 154 - (271,595 ) Operating profit 2,178,411 3,608,057 390,751 27,600 - 6,204,819 Depreciation of property, plant and equipment (1,695,112 ) (95,318 ) (229,786 ) - - (2,020,216 ) Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Total Identifiable assets 34,792,004 6,846,690 3,069,476 145,257 44,853,427 Identifiable Liabilities 15,451,091 2,176,705 1,907,129 38,913 19,573,838 Year ended December 31, 2016 Natural Gas Transportation Production and Commercialization of Liquids Other Services Telecommunications Eliminations Total Revenues 4,162,220 9,404,793 956,948 121,549 - 14,645,510 Intercompany revenues 138,502 - - - (138,502 ) - Cost of sales (3,259,674 ) (6,407,872 ) (433,877 ) (62,503 ) 138,502 (10,025,424 ) Administrative expenses (784,885 ) (61,573 ) (27,850 ) (6,459 ) - (880,767 ) Selling expenses (239,294 ) (353,913 ) (87,741 ) (14,910 ) - (695,858 ) Other operating expenses (90,032 ) (37,417 ) (2,350 ) (845 ) - (130,644 ) Operating profit (73,163 ) 2,544,018 405,130 36,832 - 2,912,817 Depreciation of property, plant and equipment (1,884,543 ) (87,926 ) (122,949 ) - - (2,095,418 )

DETAIL OF SIGNIFICANT STATEME_2

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS (Tables)	12 Months Ended
	Dec. 31, 2018
DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS [Abstract]
Other Receivables	a) Other receivables 2018 2017 Current Non Current Current Non Current VAT credit balance 300,272 - 155,570 - Other tax receivables 9,988 2,044 10,674 3,786 Prepaid expenses 47,756 - 32,162 - Advances to suppliers 1,850,997 - 554,417 - Subsidies receivables 292,866 - 255,886 - Guaranteed deposits 1,139 - - - Other Receivables UT 29,706 - 3,318 - Others 130,334 6,189 14,576 14,088 Total 2,663,058 8,233 1,026,603 17,874
Trade Receivables	b) Trade receivables 2018 2017 Current Non Current Current Non Current Commons 2,898,908 - 2,965,995 4,511 UT 20,442 - 225,565 - Natural Gas Transportation 1,657,456 - 1,314,592 - Production and Commercialization of Liquids 1,092,536 - 1,342,194 - Other services 128,474 - 83,644 4,511 Related parties (Note 21) 348,112 - 36,437 - Natural Gas Transportation 73,243 - 14,302 - Production and Commercialization of Liquids 8,124 - - - Other services 266,745 - 22,135 - Allowance for doubtful accounts (132,521 ) - - - Total 3,114,499 - 3,002,432 4,511 The movement of the allowance for doubtful accounts is as follows: For doubtful accounts Balances as of 12/31/2016 36,304 Inflation adjustment restatement (12,909 ) Additions - Applications - Decreases (1) (23,395 ) Balances as of 12/31/2017 - Additions (1) 132,521 Applications - Decreases - Balances as of 12/31/2018 132,521 (1) The total amount is recorded in Selling Expenses
Cash and Cash Equivalents	c) Cash and cash equivalents 2018 2017 Cash and banks 5,964,008 981,710 UT Cash and banks 153 695 Mutual funds 610,108 - Bank account 2,146,801 1,866,194 Interest-bearing accounts 7,909,391 973,646 UT Mutual funds 14,366 94,502 Total 16,644,827 3,916,747
Contract Liabilities	d) Contract liabilities 12/31/2018 1/1/2018 Current Non Current Current Non Current Natural Gas Transportation 67,978 1,198,855 101,990 1,257,599 Production and Commercialization of Liquids 25,514 255,075 14,546 269,614 Other services 2,018 15,121 11,888 7,927 UT 34,068 - 88,396 - Total 129,578 1,469,051 216,820 1,535,140
Advances from Customers	e) Advances from customers 2018 2017 Current Non Current Current Non Current Natural Gas Transportation - - 101,990 1,257,599 Production and Commercialization of Liquids - - 14,546 269,614 Other Services - - 11,888 7,927 UT - - 88,396 - Total - - 216,820 1,535,140
Other Payables	f) Other payables 2018 2017 Current Non Current Current Non Current UT Other liabilities 73,621 - - - Provision for compensation for the Board of Directors and Supervisory Committee Supervisory Commitee 5,409 - - - Justice fee payable - - 47,072 - Others 1,644 - 2,459 - Total 80,674 - 49,531 -
Taxes Payables	g) Taxes payables 2018 2017 Current Non Current Current Non Current Withholdings for income tax made to third parties 110,623 - 79,749 - Health and safety tax 8,790 - - - Turnover Tax 62,714 - 42,613 - UT Others 2,752 - - - Others 17,343 - 20,200 - Total 202,222 - 142,562 -
Trade Payables	h) Trade payables 2018 2017 Current Non Current Current Non Current Suppliers 2,798,453 - 1,967,080 - UT Suppliers 90,252 - 11,236 - Customers (credit balances) 2,235 - 15,851 - Related parties (Note 21) 201,097 - 151,571 - Total 3,092,037 - 2,145,738 -
Revenues	i) Revenues 2018 2017 2016 Sales of goods and services 33,655,943 19,605,611 14,331,482 Subsidies 406,727 347,655 314,028 Total 34,062,670 19,953,266 14,645,510
Disaggregation of Revenues	Below is a table in which revenues are disaggregated considering the type of market and the opportunity to satisfy performance obligations: Year ended December 31, 2018 Natural gas transportation Production and commercialization of liquids Other services Telecommunications Total Primary geographical market: External market - 6,025,445 - - 6,025,445 Domestic market 15,462,061 10,601,984 1,810,109 163,071 28,037,225 Total 15,462,061 16,627,429 1,810,109 163,071 34,062,670 Timing of revenue recognition: Over the time 15,462,061 705,309 1,810,109 163,071 18,140,550 At a point in time - 15,922,120 - - 15,922,120 Total 15,462,061 16,627,429 1,810,109 163,071 34,062,670 Year ended December 31, 2017 Natural gas transportation Production and commercialization of liquids Other services Telecommunications Total Primary geographical market: External market - 4,332,548 - - 4,332,548 Domestic market 7,456,052 6,841,427 1,199,170 124,069 15,620,718 Total 7,456,052 11,173,975 1,199,170 124,069 19,953,266 Timing of revenue recognition: Over the time 7,456,052 534,842 1,199,170 124,069 9,314,133 At a point in time - 10,639,133 - - 10,639,133 Total 7,456,052 11,173,975 1,199,170 124,069 19,953,266 Year ended December 31, 2016 Natural gas transportation Production and commercialization of liquids Other services Telecommunications Total Primary geographical market: External market - 2,841,403 - - 2,841,403 Domestic market 4,162,220 6,563,390 956,948 121,549 11,804,107 Total 4,162,220 9,404,793 956,948 121,549 14,645,510 Timing of revenue recognition: Over the time 4,162,220 570,904 956,948 121,549 5,811,621 At a point in time - 8,833,889 - - 8,833,889 Total 4,162,220 9,404,793 956,948 121,549 14,645,510 Detailed information of revenues on each business segment for the years ended December 31, 2018, 2017 and 2016 is disclosed below: i. Natural Gas Transportation: 2018 2017 2016 Firm 12,243,699 5,831,927 2,988,232 Access and Charge 565,809 433,575 420,897 Interruptible and Others 2,652,553 1,190,550 753,091 Total 15,462,061 7,456,052 4,162,220 ii. Production and Commercialization of Liquids: 2018 2017 2016 Product 15,515,393 10,255,416 8,062,864 Services 705,309 570,904 1,027,901 Government grants 406,727 347,655 314,028 Total 16,627,429 11,173,975 9,404,793 iii. Other services: 2018 2017 2016 Conditioning and treatment 735,099 546,758 410,644 Operation and maintenance 480,112 414,576 328,975 Steam sales 136,764 96,587 106,212 Construction 21,321 138,638 100,543 UT Construction 433,200 - - Others 3,613 2,611 10,574 Total 1,810,109 1,199,170 956,948
Cost of Sales	j) Cost of sales 2018 2017 2016 Inventories at the beginning of the year 183,745 241,477 240,933 Purchases 8,860,447 6,013,669 5,453,359 Operating costs (Note 8.k.) 7,504,392 5,864,281 4,572,609 Inventories at the end of the year (360,274 ) (183,745 ) (241,477 ) Total 16,188,310 11,935,682 10,025,424
Expenses by Nature	k) Expenses by nature – Information required under art. 64 paragraph I, clause B) Commercial Companies Law 2018 Operating expenses Accounts Total Regulated Activities Non Regulated Administrative expenses Selling expenses Financial expenses Salaries, wages and other compensations 1,912,950 891,140 567,798 356,913 97,099 - Social security taxes 320,232 144,748 84,940 69,616 20,928 - Compensation to Directors and Supervisory Committee 25,819 - - 25,819 - - Professional services fees 274,697 7,047 135,626 125,232 6,792 - Technical operator assistance fees 1,317,176 838,032 479,144 - - - Materials 223,940 68,688 155,252 - - - Third parties services 261,779 102,315 130,258 19,790 9,416 - Telecommunications and post expenses 21,776 4,196 2,857 14,258 465 - Rents 24,786 7,657 10,301 5,946 882 - Transports and freight 68,094 42,231 22,984 2,879 - - Easements 54,076 54,076 - - - - Offices supplies 6,997 2,371 861 3,130 635 - Travels expenses 85,273 38,173 26,740 16,396 3,964 - Insurance 66,269 38,167 23,695 4,404 3 - Property, plant and equipment maintenance 1,265,254 1,105,531 144,116 15,607 - - Depreciation of property, plant and equipment 2,223,083 1,612,884 342,706 267,493 - - Taxes and contributions 1,675,901 170,521 20,082 2,128 1,483,170 (1) - Advertising 4,856 - - - 4,856 - Doubtful accounts 132,521 - - - 132,521 - Banks expenses 12,150 - - 12,150 - - Interests expense 1,675,437 - - - - 1,675,437 Foreign exchange loss 13,122,031 - - - - 13,122,031 Other financial charges 243,524 - - - - 243,524 Costs of services rendered to third parties 165,277 - 165,277 - - - Other expenses 88,000 36,501 27,477 20,052 3,970 - Total 2018 25,271,898 5,164,278 2,340,114 961,813 1,764,701 15,040,992 (1) Includes tax on exports for Ps. 248,883 2017 Operating expenses Accounts Total Regulated Activities Non Regulated Activities Administrative expenses Selling expenses Financial expenses Salaries, wages and other compensations 1,791,444 864,168 469,199 357,902 100,175 - Social security taxes 308,469 135,826 80,500 70,258 21,885 Compensation to Directors and Supervisory Committee 13,816 - - 13,816 - - Professional services fees 99,599 2,409 4,931 83,979 8,280 - Technical operator assistance fees 577,187 260,036 317,151 - - - Materials 97,057 29,979 67,078 - - - Third parties services 206,456 85,959 103,408 17,089 - - Telecommunications and post expenses 16,093 2,150 1,972 11,196 775 - Rents 10,939 3,161 1,581 5,442 755 - Transports and freight 57,869 34,450 19,772 3,614 33 - Easements 35,265 35,265 - - - - Offices supplies 5,612 1,665 585 2,618 744 - Travels expenses 31,035 13,879 5,113 8,991 3,052 - Insurance 52,660 30,744 17,527 3,909 480 - Property, plant and equipment maintenance 1,005,258 865,572 129,280 8,639 1,767 - Depreciation of property, plant and equipment 2,020,216 1,569,839 325,104 125,273 - - Taxes and contributions 918,821 213,123 13,395 1,186 691,117 (1) - Advertising 767 - 3 - 764 - Doubtful accounts (23,395 ) - - - (23,395 ) - Banks expenses 7,217 - - 7,217 - - Interests expense 846,366 - - - - 846,366 Foreign exchange loss 1,117,201 - - - - 1,117,201 Other financial charges 167,920 - - - - 167,920 Costs of services rendered to third parties 115,272 - 115,272 - - - Other expenses 57,794 30,640 13,545 12,745 864 - Total 2017 9,536,938 4,178,865 1,685,416 733,874 807,296 2,131,487 (1) Includes tax on exports for Ps. 1,286 2016 Operating expenses Accounts Total Regulated Activities Non Regulated Activities Administrative expenses Selling expenses Financial expenses Salaries, wages and other contributions 1,603,431 796,925 393,027 321,349 92,130 - Social security taxes 276,390 128,245 66,702 61,543 19,900 - Compensation to Directors and Supervisory Committee 12,345 - - 12,345 - - Professional services fees 80,706 2,580 7,002 64,122 7,002 - Technical operator assistance fees 329,826 105,950 223,876 - - - Materials 85,497 28,376 57,121 - - - Third parties services 183,154 72,598 95,078 15,478 - - Telecommunications and post expenses 9,766 553 2,211 6,818 184 - Rents 6,818 1,658 737 4,054 369 - Transports and freight 54,541 33,904 19,347 1,290 - - Easements 38,326 38,326 - - - - Offices supplies 5,159 1,843 737 2,395 184 - Travels expenses 19,533 9,582 2,764 5,344 1,843 - Insurance 51,962 29,666 18,242 3,501 553 - Property, plant and equipment maintenance 408,504 294,447 102,080 9,766 2,211 - Depreciation of property, plant and equipment 2,095,419 1,527,999 210,876 356,544 - - Taxes and contributions 703,136 160,122 17,320 1,474 524,220 (1) - Advertising 737 - - - 737 - Doubtful accounts 38,142 - - - 38,142 - Banks expenses 4,054 - - 4,054 - - Interests expense 937,454 - - - - 937,454 Foreign exchange loss 1,486,399 - - - - 1,486,399 Other financial charges 131,536 - - - - 131,536 Derivate financial instruments 9,383 - - - - 9,383 Costs of services rendered to third parties 84,207 - 84,207 - - - Other expenses 57,581 26,900 11,608 10,690 8,383 - Year ended Deccember 31, 2016 8,714,006 3,259,674 1,312,935 880,767 695,858 2,564,772 (1) Includes tax on exports of Ps. 11,081 for the year ended December 31, 2016.
Net Financial Results	l) Net financial results 2018 2017 2016 Financial income Derivative financial instrument results 106,084 - - Interest income 1,345,278 133,116 206,402 Fair value gains on financial instruments through profit or loss 1,372,933 442,480 329,401 Foreign exchange gain 8,164,243 561,572 280,988 Subtotal 10,988,538 1,137,168 816,791 Financial expenses Interest expense (1,675,437 ) (846,366 ) (937,454 ) Foreign exchange loss (13,122,031 ) (1,117,201 ) (1,486,399 ) Derivative financial instrument results - - (9,383 ) Other financial charges (243,524 ) (167,920 ) (131,536 ) Less: C - - - Subtotal (15,040,992 ) (2,131,487 ) (2,564,772 ) Gain on net monetary results 1,206,195 465,975 1,038,647 Total (2,846,259 ) (528,344 ) (709,334 )
Other Operating Expenses	m) Other operating expenses 2018 2017 2016 Disposal of property, plant and equipment (158,516 ) (131,419 ) (16,368 ) Net increase in provisions (1) (770,802 ) (228,196 ) (124,437 ) Recovery of insurance 23,874 194,689 - Write off of other receivables - (105,047 ) - Others 14,657 (1,622 ) 10,161 Total (890,787 ) (271,595 ) (130,644 ) (1) Includes judicial costs
Other Financial Assets at Fair Value through Profit or Loss	n) Other financial assets at fair value through profit or loss 2018 2017 Current Non Current Current Non Current Government bonds - - 218,707 - Private bonds - - 106,451 - Total - - 325,158 -
Other Financial Assets at Amortized Cost	o) Other financial assets at amortized cost 2018 2017 Current Non Current Current Non Current VRD bonds 5,714 8,760 10,499 21,369 Government Bonds (Argentine National Treasury Notes) - - 1,361,756 - Government Bonds (Central Bank Notes) - - 761,856 - Total 5,714 8,760 2,134,111 21,369
Payroll and Social Security Taxes Payable	p) Payroll and social security taxes payable 2018 2017 Current Non Current Current Non Current Vacation benefit payable 170,690 - 154,643 - Annual bonus payable 133,365 - 125,344 - Social security taxes payable 67,381 - 67,287 - UT 12,200 - - - Total 383,636 - 347,274 -

INVESTMENTS IN ASSOCIATES (Tabl

INVESTMENTS IN ASSOCIATES (Tables)	12 Months Ended
	Dec. 31, 2018
INVESTMENTS IN ASSOCIATES [Abstract]
Investments in Associates	2018 2017 Issuer Information Description of securities Last financial statemets issued Name and issuer Face value Amount Cost Book value Main business Date Common stock Net (loss) / income for the year / period Shareholders’ equity % of Common Stock Book value Transporte y Servicios de Ps. Uru. 1 196,000 118 5,798 Pipeline maintenance 09/30/2018 28 (689 ) 11,832 49.00 3,981 Emprendimientos de Gas del Sur S.A. (in liquidation) $ 1 116,130 116 324 Pipeline construction and operation services 09/30/2018 237 (70 ) 661 49.00 543 Gas Link S.A. $ 1 502,962 5,587 66,548 Pipeline construction and operation services 09/30/2018 1,026 30,918 145,949 49.00 51,400 Total 72,670 55,924

JOINT ARRANGEMENTS (Tables)

JOINT ARRANGEMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
JOINT ARRANGEMENTS [Abstract]
Joint Arrangements	The breakdown of the amounts included in the statements of financial position related to the Company’s participation in the UT and as of December 31, 2018 and 2017 and for the three years ended December 31, 2018 is the following: 2018 2017 Consolidated Statements of financial position Non Current assets - - Current Assets 195,439 99,816 Total 195,439 99,816 Non Current Liabilities - - Current Liabilities 169,843 99,726 Total 169,843 99,726 2018 2017 Consolidated Statements of comprehensive income Gross profit 33,876 797 Operating profit / (loss) 24,388 (25 ) Net Financial results 1,047 226 Comprehensive income 25,435 201

PROFIT FROM ASSOCIATES (Tables)

PROFIT FROM ASSOCIATES (Tables)	12 Months Ended
	Dec. 31, 2018
PROFIT FROM ASSOCIATES [Abstract]
Profit from Associates	2018 2017 2016 EGS (in liquidation) 3,101 21 175 TGU (42 ) 285 236 Link 15,148 21,335 4,678 Total 18,207 21,641 5,089

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2018
PROPERTY, PLANT AND EQUIPMENT [Abstract]
Property, Plant and Equipment	2018 C o s t D e p r e c i a t i o n Account Beginning of the year Additions Retirements Transfers End of the year Accumulated at the beginning of the year Retirements For the year Rate % Accumulated at at the end of the year Net book value Pipelines 39,112,667 - 18,101 831,882 39,926,448 18,606,656 300 959,389 2.2 19,565,745 20,360,703 Compressor plants 14,541,520 - 308,660 1,023,210 15,256,070 9,981,767 278,943 629,861 3,3 a 25 10,332,685 4,923,385 Other plants 17,219 - - - 17,219 4,642 - 584 3.3 5,226 11,993 Stations of regulation and/or measurement of pressure 1,360,656 1,081 5,948 4,001 1,359,790 1,053,505 5,163 36,195 4.0 1,084,537 275,253 Other technical installations 264,962 - 1,330 5,308 268,940 225,092 1,330 5,742 6.7 229,504 39,436 Subtotal assets related to natural gas transportation service 55,297,024 1,081 334,039 1,864,401 56,828,467 29,871,662 285,736 1,631,771 31,217,697 25,610,770 Assets related to natural gas upstream service 3,489,476 5,971 197,269 (32,913 ) 3,265,265 1,330,045 177,846 207,557 3,3 a 25 1,359,756 1,905,509 Assets related to liquids production and commercialization service 7,030,019 - 474,602 434,953 6,990,370 5,958,293 440,455 97,677 3.3 5,615,515 1,374,855 Lands 71,837 35,511 - - 107,348 - - - - - 107,348 Buildings and constructions 1,985,027 - 48,091 90,998 2,027,934 1,147,560 38,159 35,802 2.0 1,145,203 882,731 Fittings and features in building 165,920 - 11,752 17,252 171,420 67,417 6,123 7,209 4.0 68,503 102,917 Machinery, equipment and tools 513,762 129,963 47,758 10,981 606,948 396,215 47,588 27,234 6,7 a 10 375,861 231,087 UT Machinery, equipment and tools - 591 - - 591 - - 446 6,7 a 10 446 145 Computers and Telecommunication systems 3,745,839 168 1,355,581 325,263 2,715,689 3,382,394 1,350,936 192,240 6,7 a 20 2,223,698 491,991 Vehicles 263,745 38,089 5,817 - 296,017 191,683 5,503 22,310 20 208,490 87,527 Furniture 148,460 - - 104 148,564 143,026 - 837 10 143,863 4,701 Materials 1,572,902 572,326 35,953 (572,902 ) 1,536,373 - - - - - 1,536,373 Line pack 153,720 - - 222,473 376,193 17,971 - - - 17,971 358,222 Works in progress 2,229,243 6,122,710 - (2,360,610 ) 5,991,343 - - - - - 5,991,343 Total 76,666,974 6,906,410 2,510,862 - 81,062,522 42,506,266 2,352,346 2,223,083 42,377,003 38,685,519 2017 C o s t D e p r e c i a t i o n Account Beginning of the year Additions Retirements Transfers End of the year Accumulated at the beginning of the year Retirements For the year Rate % Accumulated at at the end of the year Net book value Pipelines 38,613,449 - 17,399 516,617 39,112,667 17,678,180 63 928,539 2.2 18,606,656 20,506,011 Compressor plants 14,181,525 2,660 189,100 546,435 14,541,520 9,508,571 102,860 576,056 3,3 a 25 9,981,767 4,559,753 Other plants 17,219 - - - 17,219 4,058 - 584 3.3 4,642 12,577 Stations of regulation and/or measurement of pressure 1,350,336 - - 10,320 1,360,656 1,002,347 - 51,158 4.0 1,053,505 307,151 Other technical installations 259,919 - 11,194 16,237 264,962 219,216 187 6,063 6.7 225,092 39,870 Subtotal assets related to natural gas transportation service 54,422,448 2,660 217,693 1,089,609 55,297,024 28,412,372 103,110 1,562,400 29,871,662 25,425,362 Assets related to natural gas upstream service 3,231,072 - 2,815 261,219 3,489,476 1,123,382 100 206,763 3,3 a 25 1,330,045 2,159,431 Assets related to liquids production and commercialization service 6,839,452 - 3,922 194,489 7,030,019 5,878,107 36 80,222 3.3 5,958,293 1,071,726 Lands 71,830 7 - - 71,837 - - - - - 71,837 Buildings and constructions 1,945,894 - 1,027 40,160 1,985,027 1,112,381 5 35,184 2.0 1,147,560 837,467 Fittings and features in building 165,425 - - 495 165,920 60,396 - 7,021 4.0 67,417 98,503 Machinery, equipment and tools 430,019 82,172 - 1,571 513,762 382,173 - 14,042 6,7 a 10 396,215 117,547 UT Machinery, equipment and tools - - - - - - - - 6,7 a 10 - - Computers and Telecommunication systems 3,672,719 - - 73,120 3,745,839 3,286,123 - 96,271 6,7 a 20 3,382,394 363,445 Vehicles 235,191 49,029 20,475 - 263,745 194,679 20,475 17,479 20 191,683 72,062 Furniture 148,206 - - 254 148,460 142,192 - 834 10 143,026 5,434 Materials 1,118,657 514,263 9,213 (50,805 ) 1,572,902 - - - - - 1,572,902 Line pack 153,720 - - - 153,720 17,971 - - - 17,971 135,749 Works in progress 2,190,845 1,648,510 - (1,610,112 ) 2,229,243 - - - - - 2,229,243 Total 74,625,478 2,296,641 255,145 - 76,666,974 40,609,776 123,726 2,020,216 42,506,266 34,160,708
Disclosure of Financial Lease under Terms of Leasing Contracts	As of December 31, 2018 and 2017, the assets allocated to the natural gas treatment and compression service include the following amounts in which the Company is a financial lease under the terms of leasing contracts: 2018 2017 Cost – Capitalized financial leasing 1,429,713 1,429,713 Accumulated depreciation (222,649 ) (130,518 ) Total 1,207,064 1,299,195

LOANS (Tables)

LOANS (Tables)	12 Months Ended
	Dec. 31, 2018
LOANS [Abstract]
Short-term and Long-term Loans	Short-term and long-term loans as of December 31, 2018 and 2017 comprise the following: 2018 2017 Current Loans 2014 Notes - 1,758,428 2018 Notes Interest 227,114 55,614 Financial Leasing (Note 22) 215,722 148,567 Total Current loans 442,836 1,962,609 Non Current Loans 2014 Notes - 3,512,517 2018 Notes Interest 18,714,529 - Financial Leasing (Note 22) 1,439,687 1,167,494 Total non current loans 20,154,216 4,680,011 Total (1) 20,597,052 6,642,620 (1) Issuance expenses net for Ps. 120,420 and Ps. 12,584 as of December 31, 2018 and 2017, respectively.
Activity of Loans	The activity of the loans as of December 31, 2018 and 2017 is the following: 2018 2017 Beginning balance 6,642,620 7,217,464 Inflation adjustment restatement (7,106,426 ) (1,478,063 ) Accrued interest 1,498,556 619,727 Effect of foreign exchange rate change 12,848,796 781,956 VAT unpaid installments 19,104 7,210 Proceeds from loans 13,821,521 - Payment of loans (1) (1,328,029 ) (125,951 ) Payment of redemption of loans (4,796,243 ) - Interest paid (2) (1,002,847 ) (379,723 ) Ending balance 20,597,052 6,642,620 (1) For the years ended on December 31, 2018 and 2017, Ps. 101,968 and Ps. 66,075 respectively were cancelled through the offseting of debit balances maintained with the creditor (Pampa Energía). (2) For the years ended on December 31, 2018 and 2017, Ps. 97,101 and Ps. 77,565, respectively, were cancelled through the offseting of debit balances maintained with the creditor (Pampa Energía).
Maturities of Current and Non-Current Loans	The maturities of the current and non-current loans as of December 31, 2018 are as follows, not including issuance expenses: Less than one year 212,063 From 1/01/2020 to 12/31/2020 - From 1/01/2021 to 12/31/2021 - From 1/01/2022 onwards 18,850,000 Ending balance 19,062,063
Maturities of Finance Leases	The following are the maturities of the finance leases in force as of December 31, 2018: Due: as of 12/31/2018 56,892 To due From 1/01/2019 to 12/31/2019 158,830 From 1/01/2020 to 12/31/2020 172,178 From 1/01/2021 to 12/31/2021 186,635 From 1/01/2022 to 12/31/2022 202,306 From 1/01/2023 onwards 878,568 Ending balance 1,655,409
Future Minimum Lease Payments and Present Book Value	The following table sets reconciliation between the total of future minimum lease payments as of December 31, 2018, and their present book value: As of 12/31/2019 338,887 From 1/01/2020 to 12/31/2020 282,034 From 1/01/2021 to 12/31/2021 282,034 From 1/01/2022 to 12/31/2022 282,034 From 1/01/2023 onwards 1,014,583 Total minimum future payments 2,199,572 Future financial charges on financial leases (544,163 ) Book Value financial leases 1,655,409
Conditions of 2014 Notes	On February 7, 2014, TGS issued the 2014 Notes according to the following characteristics: 2014 Notes Amount in U.S.$ 255,451,506 Interest rate 9.625% anual Scheduled payment date Percentage of original principal amount Amortization May 14, 2014 25% May 14, 2018 25% May 14, 2019 25% May 14, 2020 25% Frequency of Interest payment Semiannual, payable el May 14 and November 14 of each year. Guarantor None
Conditions of 2018 Notes	On May 2, 2018, within the framework of the 2017 Program, the Company issued the 2018 Notes according to the following characteristics: 2018 Notes Amount in U.S.$ 500,000,000 Interest Rate 6.75% annual Issuance price 99.725% Scheduled payment date Percentage of the principal to be paid Amortization May 2, 2025 100% Frequency of interest payment Semiannual, payable on May 2 and November 2 of each year. Guarantor None

INCOME TAX AND DEFERRED TAX (Ta

INCOME TAX AND DEFERRED TAX (Tables)	12 Months Ended
	Dec. 31, 2018
INCOME TAX AND DEFERRED TAX [Abstract]
Income Tax Expense	The reconciliation between the tax computed for tax purposes and the income tax expense charged to the statement of comprehensive income in the years ended December 31, 2018, 2017 and 2016 is as follows: 2018 2017 2016 Current income tax (3,198,356 ) (2,442,608 ) (931,568 ) Special revaluation tax (1,048,000 ) - - Deferred income tax 4,233,185 2,495,685 (170,709 ) Total income tax (13,171 ) 53,077 (1,102,277 )
Net Deferred Tax Assets and Liabilities	The analysis of the net deferred tax assets and liabilities is as follows: 2018 2017 Deferred tax assets: Deferred tax assets to be recovered after more than 12 months 725,558 619,101 Deferred tax assets to be recovered after less than 12 months 103,566 112,834 Deferred tax liabilities: Deferred tax liabilities to be recovered after more than 12 months (2,949,051 ) (7,164,720 ) Deferred tax liabilities to be recovered after less than 12 months (103,638 ) (23,965 ) Deferred tax liabilities, net (2,223,565 ) (6,456,750 )
Components of Net Deferred Tax Assets and Liabilities	The components of the net deferred tax assets and liabilities as of December 31, 2018, 2017 and 2016 are the following: Deferred tax assets Allowance for doubtful accounts Tax credits discounted value loss Account receivables discounted value Provisions for legal claims and other provisions Financial lease Contract liabilities Total As of December 31, 2016 12,294 2,815 70 180,950 518,070 281,232 995,431 Charge in results (12,294 ) (2,815 ) (70 ) (68,116 ) (182,606 ) 2,405 (263,496 ) As of December 31, 2017 - - - 112,834 335,464 283,637 731,935 Charge in results - 387 2,273 (11,928 ) 72,110 34,347 97,189 As of December 31, 2018 - 387 2,273 100,906 407,574 317,984 829,124 Deferred tax liabilities Deferred sales Loans Property, plant and equipment Cash and cash equivalents Inventaries Total As of December 31, 2016 85 (8,756 ) (9,915,672 ) (14,373 ) (9,150 ) (9,947,866 ) Charge in results (85 ) 5,094 2,754,614 (2,090 ) 1,648 2,759,181 As of December 31, 2017 - (3,662 ) (7,161,058 ) (16,463 ) (7,502 ) (7,188,685 ) Charge in results 2,839 (27,419 ) 4,243,088 (78,451 ) (4,061 ) 4,135,996 As of December 31, 2018 2,839 (31,081 ) (2,917,970 ) (94,914 ) (11,563 ) (3,052,689 )
Effective Income Tax Rate Reconciliation	Income tax expense computed at the statutory tax rate on pre-tax income differs from the income tax expense for the years ended December 31, 2018, 2017 and 2016 as follows: 2018 2017 2016 Pre tax income 11,429,007 5,698,116 2,208,572 Statutory income tax rate 30 % 35 % 35 % Pre tax income at statutory income tax rate (3,428,702 ) (1,994,341 ) (773,000 ) Tax effects due to: - Inflation effect (1) 4,432,884 (187,006 ) (321,584 ) - Special revaluation tax (1,048,000 ) - - -Change in the tax rate (2) - 2,234,656 - -Non taxable income or non deductible expenses 44,482 428 (7,693 ) -Others (13,835 ) (660 ) - Total income tax (13,171 ) 53,077 (1,102,277 ) (1) Corresponds to the inflation effect on non-deferred tax assests and liabilities. (2) Corresponds to the effect of the reduction in the enacted tax rate on the net deferred tax liability according to the aforementioned.

PROVISIONS (Tables)

PROVISIONS (Tables)	12 Months Ended
	Dec. 31, 2018
PROVISIONS [Abstract]
Provisions	For legal claims and others (1) Balances as of 12/31/2016 408,002 Inflation adjustment restatement (80,163 ) Additions 225,887 ´(1) Uses (254,858 ) Reversals (8,967 ) ´(3) Balances as of 12/31/2017 289,901 Inflation adjustment restatement (112,740 ) Additions 195,156 ´(1) Uses (787 ) Reversals (362 ) ´(2) Balances as of 12/31/2018 371,168 (1) Ps. 107,419 and Ps. 152,635 are included in “Other operating expenses” and Ps. 118,468 and Ps. 77,472 in “Financial expenses” for the years ended on December 31, 2018 and 2017, respectively. (2) The total amount is recorded in “Other operating income” (3) Ps. 2,263, are included in “Other operating expenses” and Ps. 6,704 in “Financial expenses” for the year 2017.

FINANCIAL RISK MANAGEMENT (Tabl

FINANCIAL RISK MANAGEMENT (Tables)	12 Months Ended
	Dec. 31, 2018
FINANCIAL RISK MANAGEMENT [Abstract]
Net Assets/Liabilities Position and Effect on Financial Results	Net assets / liabilities position in USD 2018 2017 2016 Assets 394,369 192,764 88,463 Liabilities (588,525 ) (286,129 ) (317,952 ) Total (194,156 ) (93,365 ) (229,489 ) Effect on financial results in $ Pesos 739,849 259,923 365,543 Total 739,849 259,923 365,543
Fixed-Rate and Floating-Rate Financial Assets and Liabilities	The following table shows a breakdown of the Company’s fixed-rate and floating-rate financial assets and liabilities as of December 31, 2018 and 2017: Financial assets (1) Financial liabilities (2) 2018 2017 2018 2017 Fix interest rate 8,525,212 3,097,259 18,941,643 5,326,559 Variable interest rate 14,473 31,868 - - Total 8,539,685 3,129,127 18,941,643 5,326,559 (1) Includes mutual funds, LETES, Lebacs and bank accounts. Trade receivables do no bear interests, except for Ps. 14,473 and Ps. 31,868, which bears CER plus a spread of 8% as of December 31, 2018 and 2017, respectively. (2) Includes loans, issuance expenses and financial leasing
Monthly Short Tons	This agreement is valid between October 2018 and April 2020, according to the following monthly short tons: Period Propane Butane Natural gasoline October 2018 – April 2019 6,045 4,506 2,700 May 2019 – September 2019 - - 4,100 October 2019 9,068 7,010 4,200 November 2019 – April 2020 13,098 10,014 6,000
Current and Non-Current Trade Receivables	As of December 31, 2018 and 2017, the balance of current and non-current trade receivables, net of allowances of doubtful accounts are as follows: 2018 2017 Current trade receivables 3,247,020 3,002,432 Non-current trade receivables - 4,511 Allowances for doubful accounts (132,521 ) - Total 3,114,499 3,006,943
Significant Customers	Significant customers in terms of revenues and trade receivables (net of allowances of doubtful accounts) from natural gas transportation for the years ended December 31, 2018, 2017 and 2016 are as follows: 2018 2017 2016 Revenues Trade receivables Revenues Trade receivables Revenues MetroGas 3,222,608 375,580 1,916,408 309,208 1,166,861 Camuzzi Gas Pampeana S.A. 2,393,722 279,663 1,408,811 226,138 702,375 Naturgy Argentina 1,931,580 239,730 1,012,029 172,665 524,030 CAMMESA 1,337,714 183,249 889,716 232,175 651,592 Pampa Energía 439,556 91,684 44,683 1,302 43,034 Camuzzi Gas del Sur S.A. 534,462 56,928 310,222 46,319 156,503 Revenues from Liquids Production and Commercialization customers (including those made on behalf of third parties, from whom the Company earns a commission and trade receivables (net of allowances of doubtful accounts) for the years ended December 31, 2018, 2017 and 2016 are as follows: 2018 2017 2016 Revenues Trade receivables Revenues Trade receivables Revenues PBB Polisur 5,267,302 708,797 3,683,956 520,645 3,565,562 Petredec 858,846 - 1,377,647 433,916 - Geogas Trading S.A. 1,102,307 - 571,260 - 931,432 Shell Trading (US) Company 89,868 - 1,425,123 276,932 - Petrobras Global Trading BV 1,743,806 137,413 - - - Petroleo Brasileiro - - - - 546,476 Braskem Netherlands B.V. - - - - 42,611
Maturities of Financial Assets	Below is a detail of the maturities of the financial assets included in: (i) cash and cash equivalents, (ii) other financial assets, (iii) trade receivables, (iv) other receivables and (v) derivate financial instruments, as of December 31, 2018 and 2017: December 31-2018 Cash and cash equivalents Other financial assets Receivables (1) (2) Without specified maturity 14,485,525 - 467 With specified maturity Overdue Until 12-31-2017 - - 133,771 From 01-01-18 to 03-31-18 - - 310 From 04-01-18 to 06-30-18 - - 4,020 From 07-01-18 to 09-30-18 - - 11,400 From 10-01-18 to 12-31-18 - - 535,609 Total overdue - - 685,110 Non-due From 01-01-19 to 03-31-19 2,159,302 219,767 2,945,285 From 04-01-19 to 06-30-19 - 1,495 41,157 From 07-01-19 to 09-30-19 - 1,495 - From 10-01-19 to 12-31-19 - 1,229 - During 2020 - 3,357 5,529 During 2021 - 3,044 - During 2022 - 1,911 - During 2023 - 448 - From 2024 onwards - - - Total non-due 2,159,302 232,746 2,991,971 Total with specified maturity 2,159,302 232,746 3,677,081 Total 16,644,827 232,746 3,677,548 (1) (2) December 31-2017 Cash and cash equivalents Other financial assets Receivables (1) (2) Without specified maturity 2,943,101 - 685 With specified maturity Overdue Until 12-31-2016 - - 2,990 From 01-01-17 to 03-31-17 - - 202 From 04-01-17 to 06-30-17 - - 2,637 From 07-01-17 to 09-30-17 - - 18,736 From 10-01-17 to 12-31-17 - - 220,135 Total overdue - - 244,700 Non-Due From 01-01-18 to 03-31-18 973,646 591,525 3,017,756 From 04-01-18 to 06-30-18 - 1,533,148 3,703 From 07-01-18 to 09-30-18 - 332,232 3,188 From 10-01-18 to 12-31-18 - 2,364 3,839 During 2019 - 8,436 17,624 During 2020 - 4,954 - During 2021 - 4,494 - During 2022 - 2,822 - From 2023 onwards - 663 - Total non-due 973,646 2,480,638 3,046,110 Total with specified maturity 973,646 2,480,638 3,290,810 Total 3,916,747 2,480,638 3,291,495 (1) (2)
Maturities of Financial Liabilities	The amounts disclosed in the table are the contractual undiscounted cash flows and as a result, they do not reconcile to the amounts disclosed on the statement of financial position. These tables are made based on available information at the end of each year and may not reflect the actual amounts in the future. Therefore, the amounts disclosed are provided for illustrative purposes only: December 31, 2018 Loans Other financial liabilities Financial Leases Without specified maturity - - - With specified maturity Overdue Until 12-31-2017 - 103,597 - From 01-01-18 to 03-31-18 - 311 - From 04-01-18 to 06-30-18 - 311 - From 07-01-18 to 09-30-18 - 311 - From 10-01-18 to 12-31-18 - 311 56,891 Total overdue - 104,841 56,891 Non-due From 01-01-19 to 03-31-19 - 3,352,746 70,499 From 04-01-19 to 06-30-19 636,188 21,739 70,499 From 07-01-19 to 09-30-19 - - 70,499 From 10-01-19 to 12-31-19 636,188 - 70,499 During 2020 1,272,375 - 282,034 During 2021 1,272,375 - 282,034 During 2022 1,272,375 - 282,034 During 2023 1,272,375 - 282,034 From 2024 onwards 20,758,563 - 732,549 Total non-due 27,120,439 3,374,485 2,142,681 Total with specified maturity 27,120,439 3,479,326 2,199,572 Total 27,120,439 3,479,326 2,199,572 December 31, 2017 Loans Other financial liabilities Financial Leases Without specified maturity - - - With specified maturity Overdue Until 12-31-2016 - 109,528 - From 01-01-17 to 03-31-17 - 459 - From 04-01-17 to 06-30-17 - 459 - From 07-01-17 to 09-30-17 - 459 - From 10-01-17 to 12-31-17 - 459 41,545 Total overdue - 111,364 41,545 Non-Due From 01-01-18 to 03-31-18 - 2,300,495 51,490 From 04-01-18 to 06-30-18 2,012,300 125,344 51,490 From 07-01-18 to 09-30-18 - - 51,490 From 10-01-18 to 12-31-18 169,249 - 51,490 During 2019 2,012,300 - 205,985 During 2020 1,843,053 - 205,985 During 2021 - - 205,985 During 2022 - - 205,985 From 2023 onwards - - 741,035 Total non-due 6,036,902 2,425,839 1,770,935 Total with specified maturity 6,036,902 2,537,203 1,812,480 Total 6,036,902 2,537,203 1,812,480
Gearing Ratio	During the year ended December 31, 2018 and 2017, the gearing ratio was as follows: 2018 2017 Total debt (Note 13) 20,597,052 6,642,620 Total Equity 30,945,305 25,279,589 Total Capital 51,542,357 31,922,209 Gearing Ratio 0.40 0.21
Categories of Financial Assets and Liabilities	The categories of financial assets and liabilities as of December 31, 2018 and 2017 are as follows (According to the chosen transition method, the comparative information has not been restated. See Notes 3 and 4.d): December 31, 2018 Financial assets at fair value Financial assets held to maturity Total CURRENT ASSETS Trade receivables - 3,114,499 3,114,499 Other receivables - 424,339 424,339 Derivative financial instruments 218,272 - 218,272 Other financial assets at amortized cost - 5,714 5,714 Cash and cash equivalents 2,161,167 14,483,660 16,644,827 Total current assets 2,379,439 18,028,212 20,407,651 NON-CURRENT ASSETS Other receivables - 6,189 6,189 Other financial assets at amortized cost - 8,760 8,760 Total non-current assets - 14,949 14,949 Total assets 2,379,439 18,043,161 20,422,600 Financial liabilities at fair value Other financial liabilities Total CURRENT LIABILITIES Trade payables - 3,092,037 3,092,037 Loans - 442,836 442,836 Payroll and social security taxes payables - 309,351 309,351 Other payables - 80,674 80,674 Total current liabilities - 3,924,898 3,924,898 NON-CURRENT LIABILITIES Loans - 20,154,216 20,154,216 Total non-current liabilities - 20,154,216 20,154,216 Total liabilities - 24,079,114 24,079,114 December 31, 2017 Financial assets at fair value Financial assets held to maturity Loans and other receivables Total CURRENT ASSETS Trade receivables - - 3,002,432 3,002,432 Other receivables - - 270,464 270,464 Other financial assets at amortized cost - 2,123,611 10,500 2,134,111 Other financial assets at fair value through profit or loss 325,158 - - 325,158 Cash and cash equivalents 1,960,696 - 1,956,051 3,916,747 Total current assets 2,285,854 2,123,611 5,239,447 9,648,912 NON-CURRENT ASSETS Trade receivables - - 4,511 4,511 Other receivables - - 14,088 14,088 Other financial assets at fair value through profit or loss - - 21,369 21,369 Total non-current assets - - 39,968 39,968 Total assets 2,285,854 2,123,611 5,279,415 9,688,880 Financial liabilities at fair value Other financial liabilities Total CURRENT LIABILITIES Trade payables - 2,145,738 2,145,738 Loans - 1,962,609 1,962,609 Payroll and social security taxes payables - 282,973 282,973 Other payables - 49,531 49,531 Total current liabilities - 4,440,851 4,440,851 NON-CURRENT LIABILITIES Loans - 4,680,011 4,680,011 Total non-current liabilities - 4,680,011 4,680,011 Total liabilities - 9,120,862 9,120,862
Fair Value of Financial Assets and Liabilities	The table below shows different assets and liabilities at their fair value classified by hierarchy as of December 31, 2018 and 2017: December 31, 2018 Level 1 Level 2 Level 3 Total Financial assets at fair value Cash and cash equivalents 2,161,167 - - 2,161,167 Derivative financial instruments - 218,272 - 218,272 Total 2,161,167 218,272 - 2,379,439 December 31, 2017 Level 1 Level 2 Level 3 Total Financial assets at fair value Cash and cash equivalents 1,960,696 - - 1,960,696 Other current financial assets at fair value through profit or loss 325,158 - - 325,158 Total 2,285,854 - - 2,285,854 The following table reflects the carrying amount and estimated fair value of the 2018 Notes as of December 31, 2018, based on their quoted market price: Carrying amount Fair value 2018notes 18,941,643 17,200,060

ASSETS AND LIABILITIES IN FOR_2

ASSETS AND LIABILITIES IN FORREIGN CURRENCY (Tables)	12 Months Ended
	Dec. 31, 2018
ASSETS AND LIABILITIES IN FORREIGN CURRENCY [Abstract]
Balances of Assets and Liabilities in Foreign Currency	The balances in foreign currency as of December 31, 2018 and 2017 are detailed below: 2018 2017 Foreign currency and amount (in thousands) Exchange rate Amount in local currency Foreign currency and amount (in thousands) Amount in local currency CURRENT ASSETS Cash and cash equivalents US$ 361,017 37.500 (1) 13,538,138 US$ 70,732 1,937,122 Other financial assets at amortized cost US$ 152 37.500 (1) 5,714 US$ 49,723 1,361,756 Other financial assets at fair value through profit or loss - - US$ 11,873 325,158 Trade receivables US$ 31,507 37.500 (1) 1,181,514 US$ 57,838 1,584,011 Other receivables US$ 1,693 37.500 (1) 63,488 US$ 2,433 66,632 14,788,854 5,274,679 NON CURRENT ASSETS Trade receivables - - US$ 165 4,511 - 4,511 TOTAL ASSETS 14,788,854 5,279,190 CURRENT LIABILITIES Trade payables US$ 42,184 37.700 (2) 1,590,337 US$ 44,882 1,238,162 Loans US$ 11,746 37.700 (2) 442,836 US$ 71,278 1,962,609 2,033,173 3,200,771 NON CURRENT LIABILITIES Loans US$ 534,595 37.700 (2) 20,154,216 US$ 169,969 4,680,011 20,154,216 4,680,011 TOTAL LIABILITIES 22,187,389 7,880,782 (1) Buy exchange rate at the end of fiscal year (2) Sell exchange rate at the end of fiscal year US$: United States of America dollars

COMMON STOCK AND DIVIDENDS (Tab

COMMON STOCK AND DIVIDENDS (Tables)	12 Months Ended
	Dec. 31, 2018
COMMON STOCK AND DIVIDENDS [Abstract]
Common Stock	As of December 31, 2018, TGS’ common stock was as follows: Amount of common stock, subscribed, issued, paid in, and authorized for public offer Common Shares Class (Face value $ 1, 1 vote) Outstanding shares Treasury Shares Common Stock Class “A” 405,192,594 - 405,192,594 Class “B” 375,701,909 13,600,780 389,302,689 Total 780,894,503 13,600,780 794,495,283
Dividends Distribution	Under the powers delegated by the Shareholders’ Meeting held on April 10, 2018, the Board of Directors ordered the payment of the following cash dividends: Approval date Amount Amount per share 07/06/2018 1,125,562 1.4167 08/08/2018 1,449,300 1.8242 09/06/2018 1,754,326 2.2081

BALANCES AND TRANSACTIONS WIT_2

BALANCES AND TRANSACTIONS WITH RELATED COMPANIES (Tables)	12 Months Ended
	Dec. 31, 2018
BALANCES AND TRANSACTIONS WITH RELATED COMPANIES [Abstract]
Balances with Related Parties	The detail of significant outstanding balances for transactions entered into by TGS and its related parties as of December 31, 2018, 2017 and 2016 is as follows: 2018 2017 Company Accounts receivable Accounts payable Accounts receivable Accounts payable Controlling shareholder: CIESA - - 58 - Associate which exercises joint control on the controlling shareholder: - - Pampa Energía (1) 91,684 1,850,505 23,152 1,457,352 Associate which exercises significant influence on the controlling shareholder: - - Link 6,482 - 768 - EGS - - - 679 TGU - 6,001 - 4,383 Other related companies: - - Refinor S.A. - - - 5,218 SACDE 214,148 - - - Pampa Comercializadora S.A. 7,113 - 2,779 - Oleoductos del Valle S.A. 3,131 - 1,975 - Central Piedra Buena S.A. 25,463 - 7,661 - Transener S.A. 91 - 44 - Total 348,112 1,856,506 36,437 1,467,632 (1) Accounts payable includes Ps. 1,655,409 and Ps. 1,316,061 corresponding to the financial leasing recorded as “Loans” as of December 31, 2018 and 2017, respectively.
Transactions with Related Parties	The detail of significant transactions with related parties for the years ended December 31, 2018, 2017 and 2016 is as follows: Year ended December 31, 2018: Revenues Costs Financial results Company Natural Gas Transportation Production and commercialization of liquids Other services Gas purchase and others Compensation for technical assistance Revenues for administrative services Interest expense Controlling shareholder: CIESA - - - - - 146 - Associate which exercises joint control on the controlling shareholder: Pampa Energía 439,556 1,323 230,930 617,089 1,317,176 - 125,467 Associates with significant influence: Link - - 8,589 - - - - Other related companies: Petrolera Entre Lomas S.A. (1) - - - 2,017 - - - Oleoductos del Valle S.A. 6,149 - 8,277 - - - - Pampa Comercializadora S.A. 26,869 - - - - - - Central Piedra Buena S.A. 67,175 - - - - - - Transener S.A. - - 12,014 - - - - Experta ART - - - 11,910 - - - Total 539,749 1,323 259,810 631,016 1,317,176 146 125,467 (1) Year ended December 31, 2017: Revenues Costs Financial results Company Natural Gas Transportation Production and commercialization of liquids Other services Gas purchase and others Compensation for technical assistance Revenues for administrative services Interest expense Controlling shareholder: CIESA - - - - - 154 - Associate which exercises joint control on the controlling shareholder: Pampa Energía 44,683 93,573 116,186 227,044 577,187 - 107,731 Jointly control entity: UT - - - - - 2,115 - Associates with significant influence: Link - - 7,486 - - - - Other related companies: Oleoductos del Valle S.A. 7,460 - 1,700 - - - - Refinor S.A. - - - 5,350 - - - Petrolera Pampa S.A. - - - 40,344 - - - Petrolera Entre Lomas S.A. - - - 17,801 - - - Pampa Comercializadora S.A. 10,775 - - - - - - Central Piedra Buena S.A. 13,160 - - - - - - Central Térmica Loma La Lata S.A. - - 389 - - - - Experta ART - - - 11,949 - - - Total 76,078 93,573 125,761 302,488 577,187 2,269 107,731 Year ended December 31, 2016: Revenues Costs Financial results Company Natural Gas Transportation Production and commercialization of liquids Other services Gas purchase and others Compensation for technical assistance Revenues for administrative services Interest expense Controlling shareholder: CIESA - - - - - 244 - Associate which exercises joint control on the controlling shareholder: Pampa Energía 43,034 2,317 354,464 163,345 329,826 - 50,145 Associates with significant influence: Link - - 7,787 - - - - Other related companies: Compañía Mega 3,325 176,841 35 - - - - Braskem - 42,611 - 4,361 - - - Petroleo Brasileiro - 546,476 - - - - - Petrolera Pampa S.A. - - - 333,944 - - - Oleoductos del Valle S.A. 4,715 - - - - - - Pampa Comercializadora S.A. 7,009 - - - - - - Petrouruguay 722 95 - - - - - WEB SA 220 - - 7,262 - - - Petrolera entre Lomas S.A. - - 350 50,356 - - - Central Piedrabuena S.A. 14,162 - - - - - - Experta ART - - - - - - - Total 73,187 768,340 362,636 559,268 329,826 244 50,145

CONTRACTUAL OBLIGATIONS (Tables

CONTRACTUAL OBLIGATIONS (Tables)	12 Months Ended
	Dec. 31, 2018
CONTRACTUAL OBLIGATIONS [Abstract]
Contractual Commitments	As of December 31, 2018, the Company had the following contractual commitments: Estimated maturity date Total Due less than one year Less than one year 1-2 years 3-5 years More than 5 years Financial indebtedness (1) 27,120,439 - 1,272,376 3,817,125 2,544,750 19,486,188 Purchase obligations (2) 4,836,612 - 3,396,343 1,440,269 - - Financial Leases 2,199,572 56,892 281,995 564,068 564,050 732,567 Total 34,156,623 56,892 4,950,714 5,821,462 3,108,800 20,218,755 (1) (2)

BUSINESS DESCRIPTION (Details)

BUSINESS DESCRIPTION (Details)	12 Months Ended
	Dec. 31, 2018Extension
Business Overview [Abstract]
Term of transportation license granted	35 years
Number of extension entitled	1
Term of the extension	10 years
CIESA [Member]
Major Shareholders [Abstract]
Percentage of ownership	51.00%
Petrobras Participaciones S.L. [Member]
Major Shareholders [Abstract]
Percentage of ownership	100.00%
Pampa Energia [Member] | CIESA [Member]
Major Shareholders [Abstract]
Percentage of ownership	10.00%
Trust [Member] | CIESA [Member]
Major Shareholders [Abstract]
Percentage of ownership	40.00%
GIP, WST and PCT [Member] | CIESA [Member]
Major Shareholders [Abstract]
Percentage of ownership	50.00%
GIP [Member] | CIESA [Member]
Major Shareholders [Abstract]
Percentage of ownership	27.10%
WST [Member] | CIESA [Member]
Major Shareholders [Abstract]
Percentage of ownership	4.58%
PCT [Member] | CIESA [Member]
Major Shareholders [Abstract]
Percentage of ownership	18.32%

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES, IFRS 15 Revenue from Contracts with Customers (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
New accounting standards [Abstract]
Total advances from customers		$ 1,751,960
Current liabilities [Abstract]
Advances from customers	$ 0	216,820	[1]
Contract liabilities	129,578	0	[1]
Total		216,820
Non-current liabilities [Abstract]
Advances from customers	0	1,535,140	[1]
Contract liabilities	$ 1,469,051	0	[1]
Total		1,535,140
IFRS 15 [Member]
Current liabilities [Abstract]
Advances from customers		0
Contract liabilities		216,820
Total		216,820
Non-current liabilities [Abstract]
Advances from customers		0
Contract liabilities		1,535,140
Total		1,535,140
IFRS 15 Impact [Member]
Current liabilities [Abstract]
Advances from customers		(216,820)
Contract liabilities		216,820
Total		0
Non-current liabilities [Abstract]
Advances from customers		(1,535,140)
Contract liabilities		1,535,140
Total		$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES, IFRS 9 Financial Instruments (Details)	12 Months Ended
	Dec. 31, 2018
Cash and Banks [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Loans and other receivables
Classification under IFRS 9	Amortized cost
Mutual Funds [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Fair value through profit or loss
Classification under IFRS 9	Fair value through profit or loss
Bank Accounts [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Loans and other receivables
Classification under IFRS 9	Amortized cost
Government Bonds (BONAR 2020) [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Fair value through profit or loss
Classification under IFRS 9	Fair value through profit or loss
Private Bonds [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Fair value through profit or loss
Classification under IFRS 9	Fair value through profit or loss
Government Bonds (LETES) [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Held to maturity
Classification under IFRS 9	Amortized cost
Government Bonds (Central Bank Notes) [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Held to maturity
Classification under IFRS 9	Amortized cost
VRD Bonds [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Loans and other receivables
Classification under IFRS 9	Amortized cost
Trade Receivables [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Loans and other receivables
Classification under IFRS 9	Amortized cost
Other Receivables [Member]
Comparison of Measurement Criteria Used for Financial Assets [Abstract]
Classification under IAS 39	Loans and other receivables
Classification under IFRS 9	Amortized cost

SIGNIFICANT ACCOUNTING POLICI_6

SIGNIFICANT ACCOUNTING POLICIES, Consolidation and Regulatory Framework (Details)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Regulatory framework [Abstract]
Inflation rate		47.64%	24.79%	34.59%
Telcosur [Member]
Subsidiary [Abstract]
Company		Telcosur
Shareholding and votes		99.98%
Country		Argentina
Closing date		December 31
Main activity		Telecommunication services
CTG [Member]
Subsidiary [Abstract]
Company	[1]	CTG
Shareholding and votes	[1]	100.00%
Country	[1]	Argentina
Closing date	[1]	December 31
Main activity	[1]	Electricity related services
TGU [Member]
Associates [Abstract]
Company		TGU
Shareholding and voting		49.00%
Country		Uruguay
Main activity		Pipeline maintenance
Closing date		December 31
EGS [Member]
Associates [Abstract]
Company		EGS (“in liquidation”)
Shareholding and voting		49.00%
Country		Argentina
Main activity		Pipeline exploitation and construction
Closing date		December 31
Link [Member]
Associates [Abstract]
Company		Link
Shareholding and voting		49.00%
Country		Argentina
Main activity		Pipeline exploitation and construction
Closing date		December 31
[1]	100% of the shares of this company were acquired on August 8, 2017. At present, it is in the process of being transformed into S.A.U..

SIGNIFICANT ACCOUNTING POLICI_7

SIGNIFICANT ACCOUNTING POLICIES, Restatement of Statement of Cash Flows IAS 29 (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Effect of new standards adopted [Abstract]
Total equity according to financial statements	$ 30,945,305	$ 25,279,589	[1]	$ 19,528,403	[1]	$ 18,649,007	[1]
Total comprehensive income for the year	$ 11,415,836	5,751,193	[1]	1,106,295	[1],[2]
Previously Reported [Member]
Effect of new standards adopted [Abstract]
Total equity according to financial statements		5,319,640		2,526,378		1,695,434
Total comprehensive income for the year		2,793,266		930,678
Increase Due to Adjustment of Common Stock [Member] | IAS 29 [Member]
Effect of new standards adopted [Abstract]
Total equity according to financial statements		17,321,734		17,321,734		17,321,734
(Decrease) / Increase in Accumulated Retained Earnings [Member] | IAS 29 [Member]
Effect of new standards adopted [Abstract]
Total equity according to financial statements		2,638,215		(319,709)		$ (368,161)
Gain on Net Monetary Position [Member] | IAS 29 [Member]
Effect of new standards adopted [Abstract]
Total comprehensive income for the year		465,975		1,038,647
Restatement of Income / (Expense) Items Including Income Tax [Member] | IAS 29 [Member]
Effect of new standards adopted [Abstract]
Total comprehensive income for the year		$ 2,491,952		$ (863,030)
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

SIGNIFICANT ACCOUNTING POLICI_8

SIGNIFICANT ACCOUNTING POLICIES, Property, Plant and Equipment (Details) $ in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018ARS ($)	Dec. 31, 2017ARS ($)		Dec. 31, 2018USD ($)
Property, plant and equipment [Abstract]
Property, plant and equipment from privatization of GdE	$ 38,685,519	$ 34,160,708	[1]
Financial expense capitalized	$ 0	$ 0
GdE [member]
Property, plant and equipment [Abstract]
Percentage of common stock considered for assets value	70.00%			70.00%
Value of assets, price paid on common stock from privatization of GdE				$ 561.2
Value of common stock from provatization of GdE				801.7
Debt assumed from privatization of GdE				395
Property, plant and equipment from privatization of GdE				$ 1,196.7
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

SIGNIFICANT ACCOUNTING POLICI_9

SIGNIFICANT ACCOUNTING POLICIES, Income Tax and Deferred Income Tax through Earnings Per Share (Details) - ARS ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Income tax and deferred income tax [Abstract]
Provisions for income taxes		$ 0	$ 0
Tax on minimum presumed income ("TOMPI") [Abstract]
Statutory tax rate on TOMPI		1.00%
Term of carry forward period for excess income tax		10 years
Provisions for tax on income presumed income		$ 0	0
Equity accounts [Abstract]
Percentage of legal reserve of net income		5.00%
Percentage of legal reserve on sum of Capital stock and Adjustment to capital stock balances		20.00%
Earnings per share [Abstract]
Net income attributable to owners of the Company		$ 11,415,836	$ 5,751,193		$ 1,106,295
Average number of outstanding shares (in shares)	[1]	788,405,563	794,495,283	[2]	794,495,283	[2]
Basic and diluted earnings per share (in pesos per share)		$ 14.48	$ 7.24	[2]	$ 1.39	[1],[2]
[1]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.
[2]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

CRITICAL ACCOUNTING ESTIMATES_2

CRITICAL ACCOUNTING ESTIMATES AND JUDGMENTS (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Tax Reform [Abstract]
Income tax rate	30.00%	35.00%	35.00%
2018 [Member]
Tax Reform [Abstract]
Income tax rate	30.00%
2019 [Member]
Tax Reform [Abstract]
Income tax rate	30.00%
2020 and Onwards [Member]
Tax Reform [Abstract]
Income tax rate	25.00%

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-cash Investing and Financing Activities [Abstract]
Unpaid acquisition of PPE		$ 307,746	$ 299,598	$ 47,198
Principal payment of financial lease	[1]	101,965	$ 66,075	271,843
Leasing for PPE acquisition		$ 0		$ 1,429,713
[1]	Cancelled through compensation with trade receivables with the creditor. See Note 13.

CONSOLIDATED BUSINESS SEGMENT_3

CONSOLIDATED BUSINESS SEGMENT INFORMATION (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018ARS ($)segment	Dec. 31, 2017ARS ($)		Dec. 31, 2016ARS ($)
Operating segments [Abstract]
Revenues	$ 34,062,670	$ 19,953,266	[1]	$ 14,645,510	[1],[2]
Cost of sales	(16,188,310)	(11,935,682)	[1]	(10,025,424)	[1],[2]
Administrative expenses	(961,813)	(733,874)	[1]	(880,767)	[1],[2]
Selling expenses	(1,764,701)	(807,296)	[1]	(695,858)	[1],[2]
Other operating expenses	(890,787)	(271,595)	[1]	(130,644)	[1],[2]
Operating profit	14,257,059	6,204,819	[1]	2,912,817	[1],[2]
Depreciation of property, plant and equipment	(2,223,083)	(2,020,216)		(2,095,418)
Identifiable assets	61,943,027	44,853,427	[1]
Identifiable liabilities	$ 30,997,722	19,573,838	[1]
Reportable Segments [Member]
Operating segments [Abstract]
Number of reportable segments | segment	4
Reportable Segments [Member] | Natural Gas Transportation [Member]
Operating segments [Abstract]
Revenues	$ 15,462,061	7,456,052		4,162,220
Cost of sales	(5,164,278)	(4,178,865)		(3,259,674)
Administrative expenses	(835,134)	(597,122)		(784,885)
Selling expenses	(953,729)	(419,570)		(239,294)
Other operating expenses	(156,283)	(327,245)		(90,032)
Operating profit	8,951,051	2,178,411		(73,163)
Depreciation of property, plant and equipment	(1,880,377)	(1,695,112)		(1,884,543)
Identifiable assets	45,246,427	34,792,004
Identifiable liabilities	16,738,045	15,451,091
Reportable Segments [Member] | Production and Commercialization of Liquids [Member]
Operating segments [Abstract]
Revenues	16,627,429	11,173,975		9,404,793
Cost of sales	(10,485,998)	(7,271,556)		(6,407,872)
Administrative expenses	(84,062)	(93,720)		(61,573)
Selling expenses	(640,173)	(265,336)		(353,913)
Other operating expenses	(726,732)	64,694		(37,417)
Operating profit	4,690,464	3,608,057		2,544,018
Depreciation of property, plant and equipment	(113,737)	(95,318)		(87,926)
Identifiable assets	9,040,987	6,846,690
Identifiable liabilities	1,496,225	2,176,705
Reportable Segments [Member] | Other Services [Member]
Operating segments [Abstract]
Revenues	1,810,109	1,199,170		956,948
Cost of sales	(1,054,245)	(655,830)		(433,877)
Administrative expenses	(35,980)	(36,475)		(27,850)
Selling expenses	(143,451)	(106,916)		(87,741)
Other operating expenses	(5,445)	(9,198)		(2,350)
Operating profit	570,988	390,751		405,130
Depreciation of property, plant and equipment	(228,969)	(229,786)		(122,949)
Identifiable assets	7,554,646	3,069,476
Identifiable liabilities	12,717,432	1,907,129
Reportable Segments [Member] | Telecommunications [Member]
Operating segments [Abstract]
Revenues	163,071	124,069		121,549
Cost of sales	(82,203)	(74,592)		(62,503)
Administrative expenses	(6,637)	(6,557)		(6,459)
Selling expenses	(27,348)	(15,474)		(14,910)
Other operating expenses	(2,327)	154		(845)
Operating profit	44,556	27,600		36,832
Depreciation of property, plant and equipment	0	0		0
Identifiable assets	100,967	145,257
Identifiable liabilities	46,020	38,913
Eliminations [Member]
Operating segments [Abstract]
Revenues	(598,414)	(245,161)		(138,502)
Cost of sales	598,414	245,161		138,502
Administrative expenses	0	0		0
Selling expenses	0	0		0
Other operating expenses	0	0		0
Operating profit	0	0		0
Depreciation of property, plant and equipment	0	0		0
Eliminations [Member] | Natural Gas Transportation [Member]
Operating segments [Abstract]
Revenues	598,414	245,161		138,502
Eliminations [Member] | Production and Commercialization of Liquids [Member]
Operating segments [Abstract]
Revenues	0	0		0
Eliminations [Member] | Other Services [Member]
Operating segments [Abstract]
Revenues	0	0		0
Eliminations [Member] | Telecommunications [Member]
Operating segments [Abstract]
Revenues	$ 0	$ 0		$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

DETAIL OF SIGNIFICANT STATEME_3

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Other Receivables (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
VAT credit balance	$ 300,272	$ 155,570
Other tax receivables	9,988	10,674
Prepaid expenses	47,756	32,162
Advances to suppliers	1,850,997	554,417
Subsidies receivables	292,866	255,886
Guaranteed deposits	1,139	0
Other Receivables UT	29,706	3,318
Others	130,334	14,576
Total	2,663,058	1,026,603	[1]
Non Current [Abstract]
VAT credit balance	0	0
Other tax receivables	2,044	3,786
Prepaid expenses	0	0
Advances to suppliers	0	0
Subsidies receivables	0	0
Guaranteed deposits	0	0
Other Receivables UT	0	0
Others	6,189	14,088
Total	$ 8,233	$ 17,874	[1]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEME_4

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Trade Receivables (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017
Current [Abstract]
Commons	$ 2,898,908		$ 2,965,995
Related parties	348,112		36,437
Allowance for doubtful accounts	(132,521)		0
Total	3,114,499		3,002,432	[1]
Non Current [Abstract]
Commons	0		4,511
Related parties	0		0
Allowance for doubtful accounts	0		0
Total	0		4,511	[1]
Allowance for doubtful accounts [Abstract]
Balance at the beginning of the period	0		36,304
Inflation adjustment restatement			(12,909)
Additions	132,521	[2]	0
Applications	0		0
Decreases	0		(23,395)	[2]
Balance at the end of period	132,521		0
UT [Member]
Current [Abstract]
Commons	20,442		225,565
Non Current [Abstract]
Commons	0		0
Natural Gas Transportation [Member]
Current [Abstract]
Commons	1,657,456		1,314,592
Related parties	73,243		14,302
Non Current [Abstract]
Commons	0		0
Related parties	0		0
Production and Commercialization of Liquids [Member]
Current [Abstract]
Commons	1,092,536		1,342,194
Related parties	8,124		0
Non Current [Abstract]
Commons	0		0
Related parties	0		0
Other Services [Member]
Current [Abstract]
Commons	128,474		83,644
Related parties	266,745		22,135
Non Current [Abstract]
Commons	0		4,511
Related parties	$ 0		$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The total amount is recorded in Selling Expenses

DETAIL OF SIGNIFICANT STATEME_5

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Cash and Cash Equivalents (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	[1]	Dec. 31, 2015	[1]
Cash and cash equivalents [Abstract]
Cash and banks	$ 5,964,008	$ 981,710
UT Cash and banks	153	695
Mutual funds	610,108	0
Bank account	2,146,801	1,866,194
Interest-bearing accounts	7,909,391	973,646
UT Mutual funds	14,366	94,502
Total	$ 16,644,827	$ 3,916,747	[1]	$ 2,870,394		$ 2,163,757
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEME_6

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Contract Liabilities (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Current liabilities [abstract]
Contract liabilities	$ 129,578	$ 0	[1]
Non Current liabilities [abstract]
Contract liabilities	1,469,051	0	[1]
Revenue recognized from contracts with customers	118,820
IFRS 15 [Member]
Current liabilities [abstract]
Contract liabilities		216,820
Non Current liabilities [abstract]
Contract liabilities		1,535,140
Natural Gas Transportation [Member]
Current liabilities [abstract]
Contract liabilities	67,978
Non Current liabilities [abstract]
Contract liabilities	1,198,855
Natural Gas Transportation [Member] | IFRS 15 [Member]
Current liabilities [abstract]
Contract liabilities		101,990
Non Current liabilities [abstract]
Contract liabilities		1,257,599
Production and Commercialization of Liquids [Member]
Current liabilities [abstract]
Contract liabilities	25,514
Non Current liabilities [abstract]
Contract liabilities	255,075
Production and Commercialization of Liquids [Member] | IFRS 15 [Member]
Current liabilities [abstract]
Contract liabilities		14,546
Non Current liabilities [abstract]
Contract liabilities		269,614
Other Services [Member]
Current liabilities [abstract]
Contract liabilities	2,018
Non Current liabilities [abstract]
Contract liabilities	15,121
Other Services [Member] | IFRS 15 [Member]
Current liabilities [abstract]
Contract liabilities		11,888
Non Current liabilities [abstract]
Contract liabilities		7,927
UT [Member]
Current liabilities [abstract]
Contract liabilities	34,068
Non Current liabilities [abstract]
Contract liabilities	$ 0
UT [Member] | IFRS 15 [Member]
Current liabilities [abstract]
Contract liabilities		88,396
Non Current liabilities [abstract]
Contract liabilities		$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEME_7

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Advances from Customers (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
Advances from customers	$ 0	$ 216,820	[1]
Non Current [Abstract]
Advances from customers	0	1,535,140	[1]
Natural Gas Transportation [Member]
Current [Abstract]
Advances from customers	0	101,990
Non Current [Abstract]
Advances from customers	0	1,257,599
Production and Commercialization of Liquids [Member]
Current [Abstract]
Advances from customers	0	14,546
Non Current [Abstract]
Advances from customers	0	269,614
Other Services [Member]
Current [Abstract]
Advances from customers	0	11,888
Non Current [Abstract]
Advances from customers	0	7,927
UT [Member]
Current [Abstract]
Advances from customers	0	88,396
Non Current [Abstract]
Advances from customers	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEME_8

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Other Payables (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
UT other liabilities	$ 73,621	$ 0
Provision for compensation for the Board of Directors and Supervisory Committee Supervisory Committee	5,409	0
Justice fee payable	0	47,072
Others	1,644	2,459
Total	80,674	49,531	[1]
Non Current [Abstract]
UT other liabilities	0	0
Provision for compensation for the Board of Directors and Supervisory Committee Supervisory Commitee	0	0
Justice fee payable	0	0
Others	0	0
Total	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEME_9

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Taxes Payables (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
Withholdings and perceptions made to third parties	$ 110,623	$ 79,749
Health and safety tax	8,790	0
Turnover Tax	62,714	42,613
UT Others	2,752	0
Others	17,343	20,200
Total	202,222	142,562	[1]
Non-current [Abstract]
Withholdings and perceptions made to third parties	0	0
Health and safety tax	0	0
Turnover Tax	0	0
UT Others	0	0
Others	0	0
Total	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEM_10

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Trade Payables (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
Suppliers	$ 2,798,453	$ 1,967,080
UT Suppliers	90,252	11,236
Customers (credit balances)	2,235	15,851
Related parties	201,097	151,571
Total	3,092,037	2,145,738	[1]
Non-current [Abstract]
Suppliers	0	0
UT Suppliers	0	0
Customers (credit balances)	0	0
Related parties	0	0
Total	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEM_11

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Revenues (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Revenues [Abstract]
Sales of goods and services	$ 33,655,943	$ 19,605,611		$ 14,331,482
Subsidies	406,727	347,655		314,028
Total	$ 34,062,670	$ 19,953,266	[1]	$ 14,645,510	[1],[2]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

DETAIL OF SIGNIFICANT STATEM_12

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Disaggregarion of Revenues by Geographical Market (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Revenues [Abstract]
Revenues	$ 34,062,670	$ 19,953,266	[1]	$ 14,645,510	[1],[2]
Over the Time [Member]
Revenues [Abstract]
Revenues	18,140,550	9,314,133		5,811,621
At a Point in Time [Member]
Revenues [Abstract]
Revenues	15,922,120	10,639,133		8,833,889
External Market [Member]
Revenues [Abstract]
Revenues	6,025,445	4,332,548		2,841,403
Domestic Market [Member]
Revenues [Abstract]
Revenues	28,037,225	15,620,718		11,804,107
Reportable Segments [Member] | Natural Gas Transportation [Member]
Revenues [Abstract]
Revenues	15,462,061	7,456,052		4,162,220
Reportable Segments [Member] | Natural Gas Transportation [Member] | Over the Time [Member]
Revenues [Abstract]
Revenues	15,462,061	7,456,052		4,162,220
Reportable Segments [Member] | Natural Gas Transportation [Member] | At a Point in Time [Member]
Revenues [Abstract]
Revenues	0	0		0
Reportable Segments [Member] | Natural Gas Transportation [Member] | External Market [Member]
Revenues [Abstract]
Revenues	0	0		0
Reportable Segments [Member] | Natural Gas Transportation [Member] | Domestic Market [Member]
Revenues [Abstract]
Revenues	15,462,061	7,456,052		4,162,220
Reportable Segments [Member] | Production and Commercialization of Liquids [Member]
Revenues [Abstract]
Revenues	16,627,429	11,173,975		9,404,793
Reportable Segments [Member] | Production and Commercialization of Liquids [Member] | Over the Time [Member]
Revenues [Abstract]
Revenues	705,309	534,842		570,904
Reportable Segments [Member] | Production and Commercialization of Liquids [Member] | At a Point in Time [Member]
Revenues [Abstract]
Revenues	15,922,120	10,639,133		8,833,889
Reportable Segments [Member] | Production and Commercialization of Liquids [Member] | External Market [Member]
Revenues [Abstract]
Revenues	6,025,445	4,332,548		2,841,403
Reportable Segments [Member] | Production and Commercialization of Liquids [Member] | Domestic Market [Member]
Revenues [Abstract]
Revenues	10,601,984	6,841,427		6,563,390
Reportable Segments [Member] | Other Services [Member]
Revenues [Abstract]
Revenues	1,810,109	1,199,170		956,948
Reportable Segments [Member] | Other Services [Member] | Over the Time [Member]
Revenues [Abstract]
Revenues	1,810,109	1,199,170		956,948
Reportable Segments [Member] | Other Services [Member] | At a Point in Time [Member]
Revenues [Abstract]
Revenues	0	0		0
Reportable Segments [Member] | Other Services [Member] | External Market [Member]
Revenues [Abstract]
Revenues	0	0		0
Reportable Segments [Member] | Other Services [Member] | Domestic Market [Member]
Revenues [Abstract]
Revenues	1,810,109	1,199,170		956,948
Reportable Segments [Member] | Telecommunications [Member]
Revenues [Abstract]
Revenues	163,071	124,069		121,549
Reportable Segments [Member] | Telecommunications [Member] | Over the Time [Member]
Revenues [Abstract]
Revenues	163,071	124,069		121,549
Reportable Segments [Member] | Telecommunications [Member] | At a Point in Time [Member]
Revenues [Abstract]
Revenues	0	0		0
Reportable Segments [Member] | Telecommunications [Member] | External Market [Member]
Revenues [Abstract]
Revenues	0	0		0
Reportable Segments [Member] | Telecommunications [Member] | Domestic Market [Member]
Revenues [Abstract]
Revenues	$ 163,071	$ 124,069		$ 121,549
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

DETAIL OF SIGNIFICANT STATEM_13

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Disaggregation of Revenues by Business Segment (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Revenues [Abstract]
Revenues	$ 34,062,670	$ 19,953,266	[1]	$ 14,645,510	[1],[2]
Reportable Segments [Member] | Natural Gas Transportation [Member]
Revenues [Abstract]
Revenues	15,462,061	7,456,052		4,162,220
Reportable Segments [Member] | Natural Gas Transportation [Member] | Firm [Member]
Revenues [Abstract]
Revenues	12,243,699	5,831,927		2,988,232
Reportable Segments [Member] | Natural Gas Transportation [Member] | Access and Charge [Member]
Revenues [Abstract]
Revenues	565,809	433,575		420,897
Reportable Segments [Member] | Natural Gas Transportation [Member] | Interruptible and Others [Member]
Revenues [Abstract]
Revenues	2,652,553	1,190,550		753,091
Reportable Segments [Member] | Production and Commercialization of Liquids [Member]
Revenues [Abstract]
Revenues	16,627,429	11,173,975		9,404,793
Reportable Segments [Member] | Production and Commercialization of Liquids [Member] | Product [Member]
Revenues [Abstract]
Revenues	15,515,393	10,255,416		8,062,864
Reportable Segments [Member] | Production and Commercialization of Liquids [Member] | Services [Member]
Revenues [Abstract]
Revenues	705,309	570,904		1,027,901
Reportable Segments [Member] | Production and Commercialization of Liquids [Member] | Government Grants [Member]
Revenues [Abstract]
Revenues	406,727	347,655		314,028
Reportable Segments [Member] | Other Services [Member]
Revenues [Abstract]
Revenues	1,810,109	1,199,170		956,948
Reportable Segments [Member] | Other Services [Member] | Conditioning and Treatment [Member]
Revenues [Abstract]
Revenues	735,099	546,758		410,644
Reportable Segments [Member] | Other Services [Member] | Operation and Maintenance [Member]
Revenues [Abstract]
Revenues	480,112	414,576		328,975
Reportable Segments [Member] | Other Services [Member] | Steam Sales [Member]
Revenues [Abstract]
Revenues	136,764	96,587		106,212
Reportable Segments [Member] | Other Services [Member] | Construction [Member]
Revenues [Abstract]
Revenues	21,321	138,638		100,543
Reportable Segments [Member] | Other Services [Member] | UT Construction [Member]
Revenues [Abstract]
Revenues	433,200	0		0
Reportable Segments [Member] | Other Services [Member] | Others [Member]
Revenues [Abstract]
Revenues	3,613	2,611		10,574
Reportable Segments [Member] | Telecommunications [Member]
Revenues [Abstract]
Revenues	$ 163,071	$ 124,069		$ 121,549
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

DETAIL OF SIGNIFICANT STATEM_14

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Cost of Sales (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Reconciliation of Changes in Inventories [Abstract]
Inventories at the beginning of the year	$ 183,745	[1]	$ 241,477		$ 240,933
Puchases	8,860,447		6,013,669		5,453,359
Operating costs	7,504,392		5,864,281		4,572,609
Inventories at the end of the year	(360,274)		(183,745)	[1]	(241,477)
Total	$ 16,188,310		$ 11,935,682	[1]	$ 10,025,424	[1],[2]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

DETAIL OF SIGNIFICANT STATEM_15

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Expenses by Nature (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Expenses by Nature [abstract]
Salaries, wages and other compensations	$ 1,912,950		$ 1,791,444		$ 1,603,431
Social security taxes	320,232		308,469		276,390
Compensation to Directors and Supervisory Committee	25,819		13,816		12,345
Professional services fees	274,697		99,599		80,706
Technical operator assistance fees	1,317,176		577,187		329,826
Materials	223,940		97,057		85,497
Third parties services	261,779		206,456		183,154
Telecommunications and post expenses	21,776		16,093		9,766
Rents	24,786		10,939		6,818
Transports and freight	68,094		57,869		54,541
Easements	54,076		35,265		38,326
Offices supplies	6,997		5,612		5,159
Travels expenses	85,273		31,035		19,533
Insurance	66,269		52,660		51,962
Property, plant and equipment maintenance	1,265,254		1,005,258		408,504
Depreciation of property, plant and equipment	2,223,083		2,020,216		2,095,419
Taxes and contributions	1,675,901		918,821		703,136
Advertising	4,856		767		737
Doubtful accounts	132,521		(23,395)	[1]	38,142	[1]
Banks expenses	12,150		7,217		4,054
Interests expense	1,675,437		846,366		937,454
Foreign exchange loss	13,122,031		1,117,201		1,486,399
Other financial charges	243,524		167,920		131,536
Derivative financial instruments results	0		0		9,383
Costs of services rendered to third parties	165,277		115,272		84,207
Other expenses	88,000		57,794		57,581
Total	25,271,898		9,536,938		8,714,006
Tax on exports	248,883		1,286		11,081
Operating Expenses, Regulated Activities [Member]
Expenses by Nature [abstract]
Salaries, wages and other compensations	891,140		864,168		796,925
Social security taxes	144,748		135,826		128,245
Compensation to Directors and Supervisory Committee	0		0		0
Professional services fees	7,047		2,409		2,580
Technical operator assistance fees	838,032		260,036		105,950
Materials	68,688		29,979		28,376
Third parties services	102,315		85,959		72,598
Telecommunications and post expenses	4,196		2,150		553
Rents	7,657		3,161		1,658
Transports and freight	42,231		34,450		33,904
Easements	54,076		35,265		38,326
Offices supplies	2,371		1,665		1,843
Travels expenses	38,173		13,879		9,582
Insurance	38,167		30,744		29,666
Property, plant and equipment maintenance	1,105,531		865,572		294,447
Depreciation of property, plant and equipment	1,612,884		1,569,839		1,527,999
Taxes and contributions	170,521		213,123		160,122
Advertising	0		0		0
Doubtful accounts	0		0		0
Banks expenses	0		0		0
Interests expense	0		0		0
Foreign exchange loss	0		0		0
Other financial charges	0		0		0
Derivative financial instruments results					0
Costs of services rendered to third parties	0		0		0
Other expenses	36,501		30,640		26,900
Total	5,164,278		4,178,865		3,259,674
Operating Expenses, Non Regulated Activities [Member]
Expenses by Nature [abstract]
Salaries, wages and other compensations	567,798		469,199		393,027
Social security taxes	84,940		80,500		66,702
Compensation to Directors and Supervisory Committee	0		0		0
Professional services fees	135,626		4,931		7,002
Technical operator assistance fees	479,144		317,151		223,876
Materials	155,252		67,078		57,121
Third parties services	130,258		103,408		95,078
Telecommunications and post expenses	2,857		1,972		2,211
Rents	10,301		1,581		737
Transports and freight	22,984		19,772		19,347
Easements	0		0		0
Offices supplies	861		585		737
Travels expenses	26,740		5,113		2,764
Insurance	23,695		17,527		18,242
Property, plant and equipment maintenance	144,116		129,280		102,080
Depreciation of property, plant and equipment	342,706		325,104		210,876
Taxes and contributions	20,082		13,395		17,320
Advertising	0		3		0
Doubtful accounts	0		0		0
Banks expenses	0		0		0
Interests expense	0		0		0
Foreign exchange loss	0		0		0
Other financial charges	0		0		0
Derivative financial instruments results					0
Costs of services rendered to third parties	165,277		115,272		84,207
Other expenses	27,477		13,545		11,608
Total	2,340,114		1,685,416		1,312,935
Administrative Expenses [Member]
Expenses by Nature [abstract]
Salaries, wages and other compensations	356,913		357,902		321,349
Social security taxes	69,616		70,258		61,543
Compensation to Directors and Supervisory Committee	25,819		13,816		12,345
Professional services fees	125,232		83,979		64,122
Technical operator assistance fees	0		0		0
Materials	0		0		0
Third parties services	19,790		17,089		15,478
Telecommunications and post expenses	14,258		11,196		6,818
Rents	5,946		5,442		4,054
Transports and freight	2,879		3,614		1,290
Easements	0		0		0
Offices supplies	3,130		2,618		2,395
Travels expenses	16,396		8,991		5,344
Insurance	4,404		3,909		3,501
Property, plant and equipment maintenance	15,607		8,639		9,766
Depreciation of property, plant and equipment	267,493		125,273		356,544
Taxes and contributions	2,128		1,186		1,474
Advertising	0		0		0
Doubtful accounts	0		0		0
Banks expenses	12,150		7,217		4,054
Interests expense	0		0		0
Foreign exchange loss	0		0		0
Other financial charges	0		0		0
Derivative financial instruments results					0
Costs of services rendered to third parties	0		0		0
Other expenses	20,052		12,745		10,690
Total	961,813		733,874		880,767
Selling Expenses [Member]
Expenses by Nature [abstract]
Salaries, wages and other compensations	97,099		100,175		92,130
Social security taxes	20,928		21,885		19,900
Compensation to Directors and Supervisory Committee	0		0		0
Professional services fees	6,792		8,280		7,002
Technical operator assistance fees	0		0		0
Materials	0		0		0
Third parties services	9,416		0		0
Telecommunications and post expenses	465		775		184
Rents	882		755		369
Transports and freight	0		33		0
Easements	0		0		0
Offices supplies	635		744		184
Travels expenses	3,964		3,052		1,843
Insurance	3		480		553
Property, plant and equipment maintenance	0		1,767		2,211
Depreciation of property, plant and equipment	0		0		0
Taxes and contributions	1,483,170	[2]	691,117	[3]	524,220	[4]
Advertising	4,856		764		737
Doubtful accounts	132,521		(23,395)		38,142
Banks expenses	0		0		0
Interests expense	0		0		0
Foreign exchange loss	0		0		0
Other financial charges	0		0		0
Derivative financial instruments results					0
Costs of services rendered to third parties	0		0		0
Other expenses	3,970		864		8,383
Total	1,764,701		807,296		695,858
Financial Expenses [Member]
Expenses by Nature [abstract]
Salaries, wages and other compensations	0		0		0
Social security taxes	0		0		0
Compensation to Directors and Supervisory Committee	0		0		0
Professional services fees	0		0		0
Technical operator assistance fees	0		0		0
Materials	0		0		0
Third parties services	0		0		0
Telecommunications and post expenses	0		0		0
Rents	0		0		0
Transports and freight	0		0		0
Easements	0		0		0
Offices supplies	0		0		0
Travels expenses	0		0		0
Insurance	0		0		0
Property, plant and equipment maintenance	0		0		0
Depreciation of property, plant and equipment	0		0		0
Taxes and contributions	0		0		0
Advertising	0		0		0
Doubtful accounts	0		0		0
Banks expenses	0		0		0
Interests expense	1,675,437		846,366		937,454
Foreign exchange loss	13,122,031		1,117,201		1,486,399
Other financial charges	243,524		167,920		131,536
Derivative financial instruments results					9,383
Costs of services rendered to third parties	0		0		0
Other expenses	0		0		0
Total	$ 15,040,992		$ 2,131,487		$ 2,564,772
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	Includes tax on exports for Ps. 248,883 for the year ended December 31, 2018.
[3]	Includes tax on exports for Ps. 1,286 for the year ended December 31, 2017
[4]	Includes tax on exports of Ps. 11,081 for the year ended December 31, 2016.

DETAIL OF SIGNIFICANT STATEM_16

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Net Financial Results (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Financial income [Abstract]
Derivative financial instrument results	$ 106,084	$ 0		$ 0
Interest income	1,345,278	133,116		206,402
Fair value gains on financial instruments through profit or loss	1,372,933	442,480		329,401
Foreign exchange gain	8,164,243	561,572		280,988
Subtotal	10,988,538	1,137,168	[1]	816,791	[1],[2]
Financial expenses [Abstract]
Interests expense	(1,675,437)	(846,366)		(937,454)
Foreign exchange loss	(13,122,031)	(1,117,201)		(1,486,399)
Derivative financial instrument results	0	0		(9,383)
Other financial charges	(243,524)	(167,920)		(131,536)
Less: Capitalized borrowing costs	0	0		0
Subtotal	(15,040,992)	(2,131,487)	[1]	(2,564,772)	[1],[2]
Gain on net monetary results	1,206,195	465,975	[1]	1,038,647	[1],[2]
Total	$ (2,846,259)	$ (528,344)	[1]	$ (709,334)	[1],[2]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

DETAIL OF SIGNIFICANT STATEM_17

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Other Operating Expenses (Details) - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS [Abstract]
Disposal of property, plant and equipment		$ (158,516)	$ (131,419)		$ (16,368)
Net increase in provisions	[1]	(770,802)	(228,196)		(124,437)
Recovery of insurance		23,874	194,689		0
Write off of other receivables		0	(105,047)		0
Others		14,657	(1,622)		10,161
Total		$ (890,787)	$ (271,595)	[2]	$ (130,644)	[2],[3]
[1]	Includes judicial costs.
[2]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[3]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

DETAIL OF SIGNIFICANT STATEM_18

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Other Financial Assets at Fair Value through Profit or Loss (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
Government bonds	$ 0	$ 218,707
Private bonds	0	106,451
Total	0	325,158	[1]
Non Current [Abstract]
Government bonds	0	0
Private bonds	0	0
Total	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEM_19

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Other Financial Assets at Amortized Cost (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
VRD bonds	$ 5,714	$ 10,499
Government Bonds (Argentine National Treasury Notes)	0	1,361,756
Government Bonds (Central Bank Notes)	0	761,856
Total	5,714	2,134,111	[1]
Non Current [Abstract]
VRD bonds	8,760	21,369
Government Bonds (Argentine National Treasury Notes)	0	0
Government Bonds (Central Bank Notes)	0	0
Total	$ 8,760	$ 21,369	[1]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

DETAIL OF SIGNIFICANT STATEM_20

DETAIL OF SIGNIFICANT STATEMENT OF FINANCIAL POSITION AND STATEMENT OF COMPREHENSIVE INCOME CAPTIONS, Payroll and Social Security Taxes Payable (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current [Abstract]
Vacation benefit payable	$ 170,690	$ 154,643
Annual bonus payable	133,365	125,344
Social security taxes payable	67,381	67,287
UT	12,200	0
Total	383,636	347,274	[1]
Non Current [Abstract]
Vacation benefit payable	0	0
Annual bonus payable	0	0
Social security taxes payable	0	0
UT	0	0
Total	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

INVESTMENTS IN ASSOCIATES (Deta

INVESTMENTS IN ASSOCIATES (Details) - ARS ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	[1]	Dec. 31, 2015	[1]
Investments in associates [Abstract]
Book value	$ 72,670	$ 55,924	[1]
Common stock	18,347,477	18,667,034	[1]
Shareholders' equity	$ 30,945,305	25,279,589	[1]	$ 19,528,403		$ 18,649,007
Transporte y Servicios de Gas en Uruguay S.A.
Investments in associates [Abstract]
Face value (in pesos per share)	$ 1
Amount	$ 196,000
Cost	118
Book value	$ 5,798	3,981
Main business	Pipeline maintenance
Date	9/30/2018
Common stock	$ 28
Net (loss) / income for the year / period	(689)
Shareholders' equity	$ 11,832
% of Common Stock	49.00%
Emprendimientos de Gas del Sur S.A. [Member]
Investments in associates [Abstract]
Face value (in pesos per share)	$ 1
Amount	$ 116,130
Cost	116
Book value	$ 324	543
Main business	Pipeline construction and operation services
Date	9/30/2018
Common stock	$ 237
Net (loss) / income for the year / period	(70)
Shareholders' equity	$ 661
% of Common Stock	49.00%
Gas Link S.A.
Investments in associates [Abstract]
Face value (in pesos per share)	$ 1
Amount	$ 502,962
Cost	5,587
Book value	$ 66,548	$ 51,400
Main business	Pipeline construction and operation services
Date	9/30/2018
Common stock	$ 1,026
Net (loss) / income for the year / period	30,918
Shareholders' equity	$ 145,949
% of Common Stock	49.00%
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

JOINT ARRANGEMENTS (Details)

JOINT ARRANGEMENTS (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	[1],[2]
Consolidated Statements of financial position [Abstract]
Non Current assets	$ 38,779,711	$ 34,264,631	[1]
Current Assets	23,163,316	10,588,796	[1]
Total assets	61,943,027	44,853,427	[1]
Non Current Liabilities	23,851,361	12,676,146	[1]
Current Liabilities	7,146,361	6,897,692	[1]
Total liabilities	30,997,722	19,573,838	[1]
Consolidated Statements of comprehensive income [Abstract]
Gross profit	17,874,360	8,017,584	[1]	$ 4,620,086
Operating profit / (loss)	14,257,059	6,204,819	[1]	2,912,817
Comprehensive income	$ 11,415,836	5,751,193	[1]	$ 1,106,295
UT [Member]
Joint Arrangements [Abstract]
Ownership interest percentage	51.00%
Consolidated Statements of financial position [Abstract]
Non Current assets	$ 0	0
Current Assets	195,439	99,816
Total assets	195,439	99,816
Non Current Liabilities	0	0
Current Liabilities	169,843	99,726
Total liabilities	169,843	99,726
Consolidated Statements of comprehensive income [Abstract]
Gross profit	33,876	797
Operating profit / (loss)	24,388	(25)
Net Financial results	1,047	226
Comprehensive income	$ 25,435	$ 201
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

PROFIT FROM ASSOCIATES (Details

PROFIT FROM ASSOCIATES (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Profit from associates [Abstract]
Profit from associates	$ 18,207	$ 21,641	[1]	$ 5,089	[1],[2]
EGS (in liquidation) [Member]
Profit from associates [Abstract]
Profit from associates	3,101	21		175
TGU [Member]
Profit from associates [Abstract]
Profit from associates	(42)	285		236
Link [Member]
Profit from associates [Abstract]
Profit from associates	$ 15,148	$ 21,335		$ 4,678
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT (Details) - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year	[1]	$ 34,160,708
Depreciation		2,223,083	$ 2,020,216		$ 2,095,418
End of the year		38,685,519	34,160,708	[1]
Financial Lease [Abstract]
Cost-Capitalized financial leasing		1,429,713	1,429,713
Accumulated depreciation		(222,649)	(130,518)
Total		$ 1,207,064	1,299,195
Financial leasing agreement expiration date		Sep. 30, 2026
Pipelines [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		$ 20,506,011
End of the year		20,360,703	20,506,011
Compressor Plants [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		4,559,753
End of the year		4,923,385	4,559,753
Other Plants [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		12,577
End of the year		11,993	12,577
Stations of Regulation and/or Measurement of Pressure [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		307,151
End of the year		275,253	307,151
Other Technical Installations [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		39,870
End of the year		39,436	39,870
Subtotal Assets Related to Natural Gas Transportation Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		25,425,362
End of the year		25,610,770	25,425,362
Assets Related to Natural Gas Upstream Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		2,159,431
End of the year		1,905,509	2,159,431
Assets Related to Liquids Production and Commercialization Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,071,726
End of the year		1,374,855	1,071,726
Lands [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		71,837
End of the year		107,348	71,837
Buildings and Constructions [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		837,467
End of the year		882,731	837,467
Fittings and Features in Building [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		98,503
End of the year		102,917	98,503
Machinery, Equipment and Tools [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		117,547
End of the year		231,087	117,547
UT Machinery, Equipment and Tools [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		0
End of the year		145	0
Computers and Telecommunication Systems [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		363,445
End of the year		491,991	363,445
Vehicles [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		72,062
End of the year		87,527	72,062
Furniture [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		5,434
End of the year		4,701	5,434
Materials [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,572,902
End of the year		1,536,373	1,572,902
Line Pack [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		135,749
End of the year		358,222	135,749
Works in Progress [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		2,229,243
End of the year		5,991,343	2,229,243
Cost [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		76,666,974	74,625,478
Additions		6,906,410	2,296,641
Retirements		2,510,862	255,145
Transfers		0	0
End of the year		81,062,522	76,666,974		74,625,478
Cost [Member] | Pipelines [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		39,112,667	38,613,449
Additions		0	0
Retirements		18,101	17,399
Transfers		831,882	516,617
End of the year		39,926,448	39,112,667		38,613,449
Cost [Member] | Compressor Plants [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		14,541,520	14,181,525
Additions		0	2,660
Retirements		308,660	189,100
Transfers		1,023,210	546,435
End of the year		15,256,070	14,541,520		14,181,525
Cost [Member] | Other Plants [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		17,219	17,219
Additions		0	0
Retirements		0	0
Transfers		0	0
End of the year		17,219	17,219		17,219
Cost [Member] | Stations of Regulation and/or Measurement of Pressure [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,360,656	1,350,336
Additions		1,081	0
Retirements		5,948	0
Transfers		4,001	10,320
End of the year		1,359,790	1,360,656		1,350,336
Cost [Member] | Other Technical Installations [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		264,962	259,919
Additions		0	0
Retirements		1,330	11,194
Transfers		5,308	16,237
End of the year		268,940	264,962		259,919
Cost [Member] | Subtotal Assets Related to Natural Gas Transportation Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		55,297,024	54,422,448
Additions		1,081	2,660
Retirements		334,039	217,693
Transfers		1,864,401	1,089,609
End of the year		56,828,467	55,297,024		54,422,448
Cost [Member] | Assets Related to Natural Gas Upstream Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		3,489,476	3,231,072
Additions		5,971	0
Retirements		197,269	2,815
Transfers		(32,913)	261,219
End of the year		3,265,265	3,489,476		3,231,072
Cost [Member] | Assets Related to Liquids Production and Commercialization Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		7,030,019	6,839,452
Additions		0	0
Retirements		474,602	3,922
Transfers		434,953	194,489
End of the year		6,990,370	7,030,019		6,839,452
Cost [Member] | Lands [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		71,837	71,830
Additions		35,511	7
Retirements		0	0
Transfers		0	0
End of the year		107,348	71,837		71,830
Cost [Member] | Buildings and Constructions [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,985,027	1,945,894
Additions		0	0
Retirements		48,091	1,027
Transfers		90,998	40,160
End of the year		2,027,934	1,985,027		1,945,894
Cost [Member] | Fittings and Features in Building [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		165,920	165,425
Additions		0	0
Retirements		11,752	0
Transfers		17,252	495
End of the year		171,420	165,920		165,425
Cost [Member] | Machinery, Equipment and Tools [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		513,762	430,019
Additions		129,963	82,172
Retirements		47,758	0
Transfers		10,981	1,571
End of the year		606,948	513,762		430,019
Cost [Member] | UT Machinery, Equipment and Tools [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		0	0
Additions		591	0
Retirements		0	0
Transfers		0	0
End of the year		591	0		0
Cost [Member] | Computers and Telecommunication Systems [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		3,745,839	3,672,719
Additions		168	0
Retirements		1,355,581	0
Transfers		325,263	73,120
End of the year		2,715,689	3,745,839		3,672,719
Cost [Member] | Vehicles [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		263,745	235,191
Additions		38,089	49,029
Retirements		5,817	20,475
Transfers		0	0
End of the year		296,017	263,745		235,191
Cost [Member] | Furniture [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		148,460	148,206
Additions		0	0
Retirements		0	0
Transfers		104	254
End of the year		148,564	148,460		148,206
Cost [Member] | Materials [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,572,902	1,118,657
Additions		572,326	514,263
Retirements		35,953	9,213
Transfers		(572,902)	(50,805)
End of the year		1,536,373	1,572,902		1,118,657
Cost [Member] | Line Pack [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		153,720	153,720
Additions		0	0
Retirements		0	0
Transfers		222,473	0
End of the year		376,193	153,720		153,720
Cost [Member] | Works in Progress [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		2,229,243	2,190,845
Additions		6,122,710	1,648,510
Retirements		0	0
Transfers		(2,360,610)	(1,610,112)
End of the year		5,991,343	2,229,243		2,190,845
Depreciation [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		42,506,266	40,609,776
Retirements		2,352,346	123,726
Depreciation		2,223,083	2,020,216
End of the year		42,377,003	42,506,266		40,609,776
Depreciation [Member] | Pipelines [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		18,606,656	17,678,180
Retirements		300	63
Depreciation		$ 959,389	$ 928,539
Depreciation rate %		2.20%	2.20%
End of the year		$ 19,565,745	$ 18,606,656		17,678,180
Depreciation [Member] | Compressor Plants [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		9,981,767	9,508,571
Retirements		278,943	102,860
Depreciation		629,861	576,056
End of the year		$ 10,332,685	$ 9,981,767		9,508,571
Depreciation [Member] | Compressor Plants [Member] | Bottom of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		3.30%	3.30%
Depreciation [Member] | Compressor Plants [Member] | Top of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		25.00%	25.00%
Depreciation [Member] | Other Plants [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		$ 4,642	$ 4,058
Retirements		0	0
Depreciation		$ 584	$ 584
Depreciation rate %		3.30%	3.30%
End of the year		$ 5,226	$ 4,642		4,058
Depreciation [Member] | Stations of Regulation and/or Measurement of Pressure [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,053,505	1,002,347
Retirements		5,163	0
Depreciation		$ 36,195	$ 51,158
Depreciation rate %		4.00%	4.00%
End of the year		$ 1,084,537	$ 1,053,505		1,002,347
Depreciation [Member] | Other Technical Installations [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		225,092	219,216
Retirements		1,330	187
Depreciation		$ 5,742	$ 6,063
Depreciation rate %		6.70%	6.70%
End of the year		$ 229,504	$ 225,092		219,216
Depreciation [Member] | Subtotal Assets Related to Natural Gas Transportation Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		29,871,662	28,412,372
Retirements		285,736	103,110
Depreciation		1,631,771	1,562,400
End of the year		31,217,697	29,871,662		28,412,372
Depreciation [Member] | Assets Related to Natural Gas Upstream Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,330,045	1,123,382
Retirements		177,846	100
Depreciation		207,557	206,763
End of the year		$ 1,359,756	$ 1,330,045		1,123,382
Depreciation [Member] | Assets Related to Natural Gas Upstream Service [Member] | Bottom of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		3.30%	3.30%
Depreciation [Member] | Assets Related to Natural Gas Upstream Service [Member] | Top of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		25.00%	25.00%
Depreciation [Member] | Assets Related to Liquids Production and Commercialization Service [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		$ 5,958,293	$ 5,878,107
Retirements		440,455	36
Depreciation		$ 97,677	$ 80,222
Depreciation rate %		3.30%	3.30%
End of the year		$ 5,615,515	$ 5,958,293		5,878,107
Depreciation [Member] | Lands [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		0	0
Retirements		0	0
Depreciation		$ 0	$ 0
Depreciation rate %		0.00%	0.00%
End of the year		$ 0	$ 0		0
Depreciation [Member] | Buildings and Constructions [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		1,147,560	1,112,381
Retirements		38,159	5
Depreciation		$ 35,802	$ 35,184
Depreciation rate %		2.00%	2.00%
End of the year		$ 1,145,203	$ 1,147,560		1,112,381
Depreciation [Member] | Fittings and Features in Building [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		67,417	60,396
Retirements		6,123	0
Depreciation		$ 7,209	$ 7,021
Depreciation rate %		4.00%	4.00%
End of the year		$ 68,503	$ 67,417		60,396
Depreciation [Member] | Machinery, Equipment and Tools [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		396,215	382,173
Retirements		47,588	0
Depreciation		27,234	14,042
End of the year		$ 375,861	$ 396,215		382,173
Depreciation [Member] | Machinery, Equipment and Tools [Member] | Bottom of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		6.70%	6.70%
Depreciation [Member] | Machinery, Equipment and Tools [Member] | Top of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		10.00%	10.00%
Depreciation [Member] | UT Machinery, Equipment and Tools [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		$ 0	$ 0
Retirements		0	0
Depreciation		446	0
End of the year		$ 446	$ 0		0
Depreciation [Member] | UT Machinery, Equipment and Tools [Member] | Bottom of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		6.70%	6.70%
Depreciation [Member] | UT Machinery, Equipment and Tools [Member] | Top of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		10.00%	10.00%
Depreciation [Member] | Computers and Telecommunication Systems [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		$ 3,382,394	$ 3,286,123
Retirements		1,350,936	0
Depreciation		192,240	96,271
End of the year		$ 2,223,698	$ 3,382,394		3,286,123
Depreciation [Member] | Computers and Telecommunication Systems [Member] | Bottom of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		6.70%	6.70%
Depreciation [Member] | Computers and Telecommunication Systems [Member] | Top of Range [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Depreciation rate %		20.00%	20.00%
Depreciation [Member] | Vehicles [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		$ 191,683	$ 194,679
Retirements		5,503	20,475
Depreciation		$ 22,310	$ 17,479
Depreciation rate %		20.00%	20.00%
End of the year		$ 208,490	$ 191,683		194,679
Depreciation [Member] | Furniture [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		143,026	142,192
Retirements		0	0
Depreciation		$ 837	$ 834
Depreciation rate %		10.00%	10.00%
End of the year		$ 143,863	$ 143,026		142,192
Depreciation [Member] | Materials [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		0	0
Retirements		0	0
Depreciation		$ 0	$ 0
Depreciation rate %		0.00%	0.00%
End of the year		$ 0	$ 0		0
Depreciation [Member] | Line Pack [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		17,971	17,971
Retirements		0	0
Depreciation		$ 0	$ 0
Depreciation rate %		0.00%	0.00%
End of the year		$ 17,971	$ 17,971		17,971
Depreciation [Member] | Works in Progress [Member]
Reconciliation of changes in property, plant and equipment [Abstract]
Beginning of the year		0	0
Retirements		0	0
Depreciation		$ 0	$ 0
Depreciation rate %		0.00%	0.00%
End of the year		$ 0	$ 0		$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

LOANS, Short-term and Long-term

LOANS, Short-term and Long-term Loans (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Current Loans [Abstract]
2014 Notes	$ 0		$ 1,758,428
2018 Notes Interest	227,114		55,614
Financial Leasing	215,722		148,567
Total Current loans	442,836		1,962,609	[1]
Non Current Loans [Abstract]
2014 Notes	0		3,512,517
2018 Notes Interest	18,714,529		0
Financial Leasing	1,439,687		1,167,494
Total non current loans	20,154,216		4,680,011	[1]
Total	20,597,052	[2]	6,642,620	[2]	$ 7,217,464
Issuance expenses	$ 120,420		$ 12,584
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	Issuance expenses net for Ps. 120,420 and Ps. 12,584 as of December 31, 2018 and 2017, respectively.

LOANS, Activity of Loans (Detai

LOANS, Activity of Loans (Details) - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Activity of Loans [Abstract]
Beginning balance		$ 6,642,620	[1]	$ 7,217,464
Inflation adjustment restatement		(7,106,426)		(1,478,063)
Accrued interest		1,498,556		619,727
Effect of foreign exchange rate change		12,848,796		781,956
VAT unpaid installments		19,104		7,210
Proceeds from loans		13,821,521		0	[2]	$ 0	[2]
Payment of loans	[3]	(1,328,029)		(125,951)
Payment of redemption of loans		(4,796,243)		0
Interest paid	[4]	(1,002,847)		(379,723)
Ending balance		20,597,052	[1]	6,642,620	[1]	$ 7,217,464
Amount cancelled through offsetting of principal payments maintained with creditor		101,968		66,075
Amount cancelled through offsetting of interest paid maintained with creditor		$ 97,101		$ 77,565
[1]	Issuance expenses net for Ps. 120,420 and Ps. 12,584 as of December 31, 2018 and 2017, respectively.
[2]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[3]	For the years ended on December 31, 2018 and 2017, Ps. 101,968 and Ps. 66,075 respectively were cancelled through the offseting of debit balances maintained with the creditor (Pampa Energia).
[4]	For the years ended on December 31, 2018 and 2017, Ps. 97,101 and Ps. 77,565, respectively, were cancelled through the offseting of debit balances maintained with the creditor (Pampa Energia).

LOANS, Maturities of Current an

LOANS, Maturities of Current and Non-current Loans (Details) $ in Thousands	Dec. 31, 2018ARS ($)
Maturities of current and non-current loans [Abstract]
Current and non-current loans excluding issuance cost	$ 19,062,063
Less than 1 year [Member]
Maturities of current and non-current loans [Abstract]
Current and non-current loans excluding issuance cost	212,063
From 01/01/2020 to 12/31/2020 [Member]
Maturities of current and non-current loans [Abstract]
Current and non-current loans excluding issuance cost	0
From 01/01/2021 to 12/31/2021 [Member]
Maturities of current and non-current loans [Abstract]
Current and non-current loans excluding issuance cost	0
From 1/01/2022 onwards [Member]
Maturities of current and non-current loans [Abstract]
Current and non-current loans excluding issuance cost	$ 18,850,000

LOANS, Maturities of Finance Le

LOANS, Maturities of Finance Leases and Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2018ARS ($)
Disclosure of maturities of finance leases and future minimum lease payments [Abstract]
Total minimum future payments	$ 2,199,572
Future financial charges on financial leases	(544,163)
Book value financial leases	1,655,409
As of 12/31/2018 [Member]
Disclosure of maturities of finance leases and future minimum lease payments [Abstract]
Book value financial leases	56,892
From 1/01/2019 to 12/31/2019 [Member]
Disclosure of maturities of finance leases and future minimum lease payments [Abstract]
Total minimum future payments	338,887
Book value financial leases	158,830
From 01/01/2020 to 12/31/2020 [Member]
Disclosure of maturities of finance leases and future minimum lease payments [Abstract]
Total minimum future payments	282,034
Book value financial leases	172,178
From 01/01/2021 to 12/31/2021 [Member]
Disclosure of maturities of finance leases and future minimum lease payments [Abstract]
Total minimum future payments	282,034
Book value financial leases	186,635
From 1/01/2022 to 12/31/2022 [Member]
Disclosure of maturities of finance leases and future minimum lease payments [Abstract]
Total minimum future payments	282,034
Book value financial leases	202,306
From 1/01/2023 onwards [Member]
Disclosure of maturities of finance leases and future minimum lease payments [Abstract]
Total minimum future payments	1,014,583
Book value financial leases	$ 878,568

LOANS, 2014 and 2018 Notes (Det

LOANS, 2014 and 2018 Notes (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2018ARS ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017ARS ($)
Issuance of notes [Abstract]
Repurchase of note	[1]	$ 1,328,029		$ 125,951
Cancellation and redemption of note		$ 4,796,243		$ 0
2014 EMTN Program [Member] | Top of Range [Member]
Issuance of notes [Abstract]
Maximum principal amount			$ 400,000,000
2014 Note [Member]
Issuance of notes [Abstract]
Principal amount			$ 255,451,506
Interest rate			9.625%
Frequency of interest payment		Semiannual, payable el May 14 and November 14 of each year	Semiannual, payable el May 14 and November 14 of each year
Guarantor		None	None
Percentage of cash flows discounted at an effective rate			10.126%
Repurchase of note			$ 86,511,165
Cancellation and redemption of note			$ 120,786,581
2014 Note [Member] | May 14, 2014 [Member]
Issuance of notes [Abstract]
Percentage of original principal amount			25.00%
2014 Note [Member] | May 14, 2018 [Member]
Issuance of notes [Abstract]
Percentage of original principal amount			25.00%
2014 Note [Member] | May 14, 2019 [Member]
Issuance of notes [Abstract]
Percentage of original principal amount			25.00%
2014 Note [Member] | May 14, 2020 [Member]
Issuance of notes [Abstract]
Percentage of original principal amount			25.00%
2018 Note [Member]
Issuance of notes [Abstract]
Principal amount			$ 500,000,000
Interest rate			6.75%
Issuance price			99.725%
Frequency of interest payment		Semiannual, payable el May 2 and November 2 of each year	Semiannual, payable el May 2 and November 2 of each year
Guarantor		None	None
Percentage of cash flows discounted at an effective rate			7.088%
2018 Note [Member] | May 2, 2025 [Member]
Issuance of notes [Abstract]
Percentage of original principal amount			100.00%
2018 Note [Member] | Top of Range [Member]
Issuance of notes [Abstract]
Maximum principal amount			$ 700,000,000
[1]	For the years ended on December 31, 2018 and 2017, Ps. 101,968 and Ps. 66,075 respectively were cancelled through the offseting of debit balances maintained with the creditor (Pampa Energia).

LOANS, Covenants and Financial

LOANS, Covenants and Financial leasing (Details)	12 Months Ended
	Dec. 31, 2018USD ($)Installment
Financial Leasing [Abstract]
Number of monthly installments | Installment	119
Bottom of Range [Member]
Covenants [Abstract]
Consolidated coverage ratio	2
Top of Range [Member]
Covenants [Abstract]
Consolidated debt ratio	3.5
Pampa Energia [Member]
Financial Leasing [Abstract]
Monthly payment amount | $	$ 623,457
Period of option to purchase financial leasing agreement for same amount	120 months

INCOME TAX AND DEFERRED TAX (De

INCOME TAX AND DEFERRED TAX (Details)	12 Months Ended
	Dec. 31, 2018ARS ($)Installment	Dec. 31, 2017	Dec. 31, 2016
Reduction in the applicable rate [Abstract]
Income tax rate	30.00%	35.00%	35.00%
Additional tax depending on dividends distributed at the rate of 30%	7.00%
Additional tax depending on dividends distributed at the rate of 25%	13.00%
Tax Adjustment For Inflation [Abstract]
Adjustment for tax inflation	47.00%
Tax Revaluation [Abstract]
One-time payment for option used | $	$ 1,048,000
Number of consecutive monthly installments | Installment	5
Bottom of Range [Member]
Tax Revaluation [Abstract]
Special tax, percentage	8.00%
Top of Range [Member]
Tax Revaluation [Abstract]
Special tax, percentage	15.00%
2018 [Member]
Reduction in the applicable rate [Abstract]
Income tax rate	30.00%
2019 [Member]
Reduction in the applicable rate [Abstract]
Income tax rate	30.00%
2020 and Onwards [Member]
Reduction in the applicable rate [Abstract]
Income tax rate	25.00%

INCOME TAX AND DEFERRED TAX, In

INCOME TAX AND DEFERRED TAX, Income Tax (Expense)/Gain (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
INCOME TAX AND DEFERRED TAX [Abstract]
Current income tax	$ (3,198,356)	$ (2,442,608)		$ (931,568)
Special revaluation tax	(1,048,000)	0		0
Deferred income tax	4,233,185	2,495,685		(170,709)
Income tax (expense) / gain	$ (13,171)	$ 53,077	[1]	$ (1,102,277)	[1],[2]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

INCOME TAX AND DEFERRED TAX, An

INCOME TAX AND DEFERRED TAX, Analysis of Deferred Tax Assets and Liabilities (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets [Abstract]
Deferred tax assets to be recovered after more than 12 months	$ 725,558	$ 619,101
Deferred tax assets to be recovered after less than 12 months	103,566	112,834
Deferred tax liabilities [Abstract]
Deferred tax liabilities to be recovered after more than 12 months	(2,949,051)	(7,164,720)
Deferred tax liabilities to be recovered after less than 12 months	(103,638)	(23,965)
Deferred tax liabilities, net	$ (2,223,565)	$ (6,456,750)

INCOME TAX AND DEFERRED TAX, Co

INCOME TAX AND DEFERRED TAX, Component of Net Deferred Tax Assets and Liabilities (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	$ (6,456,750)
Deferred tax assets (liability), end of year	(2,223,565)	$ (6,456,750)
Deferred Tax Assets [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	731,935	995,431
Charge in results	97,189	(263,496)
Deferred tax assets (liability), end of year	829,124	731,935
Deferred Tax Assets [Member] | Allowance for Doubtful Accounts [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	0	12,294
Charge in results	0	(12,294)
Deferred tax assets (liability), end of year	0	0
Deferred Tax Assets [Member] | Tax Credits Discounted Value Loss [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	0	2,815
Charge in results	387	(2,815)
Deferred tax assets (liability), end of year	387	0
Deferred Tax Assets [Member] | Account Receivables Discounted Value [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	0	70
Charge in results	2,273	(70)
Deferred tax assets (liability), end of year	2,273	0
Deferred Tax Assets [Member] | Provisions for Legal Claims and Other Provisions [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	112,834	180,950
Charge in results	(11,928)	(68,116)
Deferred tax assets (liability), end of year	100,906	112,834
Deferred Tax Assets [Member] | Financial Lease [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	335,464	518,070
Charge in results	72,110	(182,606)
Deferred tax assets (liability), end of year	407,574	335,464
Deferred Tax Assets [Member] | Contract liabilities [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	283,637	281,232
Charge in results	34,347	2,405
Deferred tax assets (liability), end of year	317,984	283,637
Deferred Tax Liabilities [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	(7,188,685)	(9,947,866)
Charge in results	4,135,996	2,759,181
Deferred tax assets (liability), end of year	(3,052,689)	(7,188,685)
Deferred Tax Liabilities [Member] | Deferred Sales [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	0	85
Charge in results	2,839	(85)
Deferred tax assets (liability), end of year	2,839	0
Deferred Tax Liabilities [Member] | Loans [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	(3,662)	(8,756)
Charge in results	(27,419)	5,094
Deferred tax assets (liability), end of year	(31,081)	(3,662)
Deferred Tax Liabilities [Member] | Property, Plant and Equipment [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	(7,161,058)	(9,915,672)
Charge in results	4,243,088	2,754,614
Deferred tax assets (liability), end of year	(2,917,970)	(7,161,058)
Deferred Tax Liabilities [Member] | Cash and Cash Equivalents [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	(16,463)	(14,373)
Charge in results	(78,451)	(2,090)
Deferred tax assets (liability), end of year	(94,914)	(16,463)
Deferred Tax Liabilities [Member] | Inventories [Member]
Components of Net Deferred Tax Assets and Liabilities [abstract]
Deferred tax assets (liability), beginning of year	(7,502)	(9,150)
Charge in results	(4,061)	1,648
Deferred tax assets (liability), end of year	$ (11,563)	$ (7,502)

INCOME TAX AND DEFERRED TAX, Ef

INCOME TAX AND DEFERRED TAX, Effective Income Tax Rate Reconciliation (Details) - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Effective Income Tax Rate Reconciliation [abstract]
Pre-tax income		$ 11,429,007	$ 5,698,116	[1]	$ 2,208,572	[1],[2]
Statutory income tax rate		30.00%	35.00%		35.00%
Pre-tax income at statutory income tax rate		$ (3,428,702)	$ (1,994,341)		$ (773,000)
Tax Effects Due to [Abstract]
Inflation effect	[3]	4,432,884	(187,006)		(321,584)
Special revaluation tax		(1,048,000)	0		0
Change in the tax rate	[4]	0	2,234,656		0
Non-taxable income or non-deductible expenses		44,482	428		(7,693)
Others		(13,835)	(660)		0
Income tax (expense) / gain		$ (13,171)	$ 53,077	[1]	$ (1,102,277)	[1],[2]
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.
[3]	Corresponds to the inflation effect on non-deferred tax assests and liabilities.
[4]	Corresponds to the effect of the reduction in the enacted tax rate on the net deferred tax liability according to the aforementioned.

PROVISIONS (Details)

PROVISIONS (Details) - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017
Legal Claims and Others [Member]
Reconciliation of changes in other provisions [abstract]
Beginning balance		$ 289,901		$ 408,002
Inflation adjustment restatement		(112,740)		(80,163)
Additions	[1]	195,156		225,887
Uses		(787)		(254,858)
Reversals		(362)	[2]	(8,967)	[3]
Ending balance		371,168		289,901
Other Operating Expenses [Member]
Reconciliation of changes in other provisions [abstract]
Additions		107,419		152,635
Reversals				(2,263)
Financial Expenses [Member]
Reconciliation of changes in other provisions [abstract]
Additions		$ 118,468		77,472
Reversals				$ (6,704)
[1]	Ps. 107,419 and Ps. 152,635 are included in "Other operating expenses" and Ps. 118,468 and Ps. 77,472 in "Financial expenses" for the years ended on December 31, 2018 and 2017 respectively.
[2]	The total amount is recorded in "Other operating income"
[3]	Ps. 2,263, are included in "Other operating expenses" and Ps. 6,704 in "Financial expenses" for the year 2017.

FINANCIAL RISK MANAGEMENT, Fore

FINANCIAL RISK MANAGEMENT, Foreign Exchange Risk (Details) $ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018ARS ($)	Dec. 31, 2017ARS ($)		Dec. 31, 2016ARS ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Net assets / liabilities position [Abstract]
Assets	$ 61,943,027	$ 44,853,427	[1]
Liabilities	$ (30,997,722)	(19,573,838)	[1]
Foreign Exchange Risk [Member]
Foreign exchange risk [Abstract]
Percentage of funds denominated in US dollars to mitigate foreign exchange risk	74.00%				74.00%
Percentage appreciation (depreciation) of US Dollar against Argentine Peso	10.00%
Net assets / liabilities position [Abstract]
Assets					$ 394,369	$ 192,764	$ 88,463
Liabilities					(588,525)	(286,129)	(317,952)
Net assets/ liabilities position					$ (194,156)	$ (93,365)	$ (229,489)
Effect on financial results [Abstract]
Effect on financial results	$ 739,849	$ 259,923		$ 365,543
U.S. Dollars [Member] | Liquids Production and Commercialization [Member] | Foreign Exchange Risk [Member]
Foreign exchange risk [Abstract]
Percentage of revenue	77.00%	76.00%		79.00%
Argentine Pesos [Member] | Liquids Production and Commercialization [Member] | Foreign Exchange Risk [Member]
Foreign exchange risk [Abstract]
Percentage of revenue	59.00%	51.00%		43.00%
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

FINANCIAL RISK MANAGEMENT, Inte

FINANCIAL RISK MANAGEMENT, Interest Rate Risk (Details) - ARS ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Financial Assets and Financial Liabilities [Abstract]
Financial assets		$ 20,422,600	$ 9,688,880
Financial liabilities		24,079,114	9,120,862
Trade receivables		3,114,499	3,006,943
Interest Rate Risk [Member]
Financial Assets and Financial Liabilities [Abstract]
Financial assets	[1]	8,539,685	3,129,127
Financial liabilities	[2]	$ 18,941,643	5,326,559
Decrease in variable rate basis		100
Interest Rate Risk [Member] | Fixed Interest Rate [Member]
Interest Rate Risk [abstract]
Percentage of outstanding financial indebtedness bearing fixed interest rate		100.00%
Financial Assets and Financial Liabilities [Abstract]
Financial assets	[1]	$ 8,525,212	3,097,259
Financial liabilities	[2]	18,941,643	5,326,559
Interest Rate Risk [Member] | Variable Interest Rate [Member]
Financial Assets and Financial Liabilities [Abstract]
Financial assets	[1]	14,473	31,868
Financial liabilities	[2]	0	0
Trade receivables		$ 14,473	$ 31,868
Interest Rate Risk [Member] | CER [Member]
Financial Assets and Financial Liabilities [Abstract]
Spread on variable interest rate		8.00%	8.00%
[1]	Includes mutual funds, LETES, Lebacs and bank accounts.Trade receivables do no bear interests, except for Ps. 14,473 and Ps. 31,868, which bears CER plus a spread of 8% as of December 31, 2018 and 2017, respectively.
[2]	Includes loans, issuance expenses and financial leasing

FINANCIAL RISK MANAGEMENT, Comm

FINANCIAL RISK MANAGEMENT, Commodity Price Risk (Details) $ in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018ARS ($)Ton$ / Ton	Dec. 31, 2017ARS ($)$ / Ton		Dec. 31, 2016ARS ($)$ / Ton	Dec. 31, 2018USD ($)
Monthly Short Tons [Abstract]
Derivative financial instruments | $	$ 218,272	$ 0	[1]
Commodity Price Risk [Member]
Commodity Rate Risk [Abstract]
Percentage of sales of propane and butane in domestic market	59.00%
Increase (decrease) in international price of LPG and natural gasoline | $ / Ton	50	50		50
Monthly Short Tons [Abstract]
Premium paid | $					$ 3
Derivative financial instruments | $	$ 218,272
Commodity Price Risk [Member] | Propane [Member] | October 2018 - April 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	6,045
Commodity Price Risk [Member] | Propane [Member] | May 2019 - September 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	0
Commodity Price Risk [Member] | Propane [Member] | October 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	9,068
Commodity Price Risk [Member] | Propane [Member] | November 2019 - April 2020 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	13,098
Commodity Price Risk [Member] | Butane [Member] | October 2018 - April 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	4,506
Commodity Price Risk [Member] | Butane [Member] | May 2019 - September 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	0
Commodity Price Risk [Member] | Butane [Member] | October 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	7,010
Commodity Price Risk [Member] | Butane [Member] | November 2019 - April 2020 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	10,014
Commodity Price Risk [Member] | Natural Gasoline [Member] | October 2018 - April 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	2,700
Commodity Price Risk [Member] | Natural Gasoline [Member] | May 2019 - September 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	4,100
Commodity Price Risk [Member] | Natural Gasoline [Member] | October 2019 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	4,200
Commodity Price Risk [Member] | Natural Gasoline [Member] | November 2019 - April 2020 [Member]
Monthly Short Tons [Abstract]
Monthly short tons	6,000
Commodity Price Risk [Member] | Liquids Production and Commercialization [Member]
Commodity Rate Risk [Abstract]
Decrease in net comprehensive income due to commodity risk | $	$ 552,004	$ 449,231		$ 233,323
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

FINANCIAL RISK MANAGEMENT, Cred

FINANCIAL RISK MANAGEMENT, Credit Risk, Trade and Other Receivables (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Trade and other receivables [abstract]
Current trade receivables	$ 3,247,020	$ 3,002,432
Non-current trade receivables	0	4,511	[1]
Allowances for doubtful accounts	(132,521)	0		$ (36,304)
Revenues	34,062,670	19,953,266	[1]	14,645,510	[1],[2]
Trade receivables	3,114,499	3,006,943
Natural Gas Transportation [Member] | MetroGas [Member]
Trade and other receivables [abstract]
Revenues	3,222,608	1,916,408		1,166,861
Trade receivables	375,580	309,208
Natural Gas Transportation [Member] | Camuzzi Gas Pampeana S.A. [Member]
Trade and other receivables [abstract]
Revenues	2,393,722	1,408,811		702,375
Trade receivables	279,663	226,138
Natural Gas Transportation [Member] | Naturgy Argentina [Member]
Trade and other receivables [abstract]
Revenues	1,931,580	1,012,029		524,030
Trade receivables	239,730	172,665
Natural Gas Transportation [Member] | CAMMESA [Member]
Trade and other receivables [abstract]
Revenues	1,337,714	889,716		651,592
Trade receivables	183,249	232,175
Natural Gas Transportation [Member] | Pampa Energia [Member]
Trade and other receivables [abstract]
Revenues	439,556	44,683		43,034
Trade receivables	91,684	1,302
Natural Gas Transportation [Member] | Camuzzi Gas del Sur S.A. [Member]
Trade and other receivables [abstract]
Revenues	534,462	310,222		156,503
Trade receivables	56,928	46,319
Liquids Production and Commercialization [Member] | PBB Polisur [Member]
Trade and other receivables [abstract]
Revenues	5,267,302	3,683,956		3,565,562
Trade receivables	708,797	520,645
Liquids Production and Commercialization [Member] | Petredec [Member]
Trade and other receivables [abstract]
Revenues	858,846	1,377,647		0
Trade receivables	0	433,916
Liquids Production and Commercialization [Member] | Geogas Trading S.A. [Member]
Trade and other receivables [abstract]
Revenues	1,102,307	571,260		931,432
Trade receivables	0	0
Liquids Production and Commercialization [Member] | Shell Trading (US) Company [Member]
Trade and other receivables [abstract]
Revenues	89,868	1,425,123		0
Trade receivables	0	276,932
Liquids Production and Commercialization [Member] | Petrobras Global Trading BV [Member]
Trade and other receivables [abstract]
Revenues	1,743,806	0		0
Trade receivables	137,413	0
Liquids Production and Commercialization [Member] | Petroleo Brasileiro [Member]
Trade and other receivables [abstract]
Revenues	0	0		546,476
Trade receivables	0	0
Liquids Production and Commercialization [Member] | Braskem Netherlands B.V. [Member]
Trade and other receivables [abstract]
Revenues	0	0		$ 42,611
Trade receivables	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	The weighted average of the number of shares considers the effect of the weighted average of the changes originated in the transactions with treasury shares made during the year.

FINANCIAL RISK MANAGEMENT, Cr_2

FINANCIAL RISK MANAGEMENT, Credit Risk, Cash and Financial Placement Maturities (Details) - ARS ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	[1]	Dec. 31, 2015	[1]
Maturities of financial assets [Abstract]
Cash and cash equivalents		$ 16,644,827	$ 3,916,747	[1]	$ 2,870,394		$ 2,163,757
Other financial assets		232,746	2,480,638
Receivables	[2],[3]	3,677,548	3,291,495
Without Specified Maturity [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		14,485,525	2,943,101
Other financial assets		0	0
Receivables	[2],[3]	467	685
With Specified Maturity Over Due [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0	0
Other financial assets		0	0
Receivables	[2],[3]	685,110	244,700
With Specified Maturity Over Due [Member] | Until 12-31-2017 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		0
Receivables	[2],[3]	133,771
With Specified Maturity Over Due [Member] | From 01-01-18 to 03-31-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		0
Receivables	[2],[3]	310
With Specified Maturity Over Due [Member] | From 04-01-18 to 06-30-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		0
Receivables	[2],[3]	4,020
With Specified Maturity Over Due [Member] | From 07-01-18 to 09-30-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		0
Receivables	[2],[3]	11,400
With Specified Maturity Over Due [Member] | From 10-01-18 to 12-31-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		0
Receivables	[2],[3]	535,609
With Specified Maturity Over Due [Member] | Until 12-31-2016 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			0
Receivables	[2],[3]		2,990
With Specified Maturity Over Due [Member] | From 01-01-17 to 03-31-17 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			0
Receivables	[2],[3]		202
With Specified Maturity Over Due [Member] | From 04-01-17 to 06-30-17 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			0
Receivables	[2],[3]		2,637
With Specified Maturity Over Due [Member] | From 07-01-17 to 09-30-17 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			0
Receivables	[2],[3]		18,736
With Specified Maturity Over Due [Member] | From 10-01-17 to 12-31-17 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			0
Receivables	[2],[3]		220,135
With Specified Maturity Non-Due [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		2,159,302	973,646
Other financial assets		232,746	2,480,638
Receivables	[2],[3]	2,991,971	3,046,110
With Specified Maturity Non-Due [Member] | From 01-01-19 to 03-31-19 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		2,159,302
Other financial assets		219,767
Receivables	[2],[3]	2,945,285
With Specified Maturity Non-Due [Member] | From 04-01-19 to 06-30-19 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		1,495
Receivables	[2],[3]	41,157
With Specified Maturity Non-Due [Member] | From 07-01-19 to 09-30-19 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		1,495
Receivables	[2],[3]	0
With Specified Maturity Non-Due [Member] | From 10-01-19 to 12-31-19 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		1,229
Receivables	[2],[3]	0
With Specified Maturity Non-Due [Member] | From 01-01-18 to 03-31-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			973,646
Other financial assets			591,525
Receivables	[2],[3]		3,017,756
With Specified Maturity Non-Due [Member] | From 04-01-18 to 06-30-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			1,533,148
Receivables	[2],[3]		3,703
With Specified Maturity Non-Due [Member] | From 07-01-18 to 09-30-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			332,232
Receivables	[2],[3]		3,188
With Specified Maturity Non-Due [Member] | From 10-01-18 to 12-31-18 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			2,364
Receivables	[2],[3]		3,839
With Specified Maturity Non-Due [Member] | During 2020 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		3,357
Receivables	[2],[3]	5,529
With Specified Maturity Non-Due [Member] | During 2021 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		3,044
Receivables	[2],[3]	0
With Specified Maturity Non-Due [Member] | During 2022 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		1,911
Receivables	[2],[3]	0
With Specified Maturity Non-Due [Member] | During 2023 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		448
Receivables	[2],[3]	0
With Specified Maturity Non-Due [Member] | From 2024 onwards [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		0
Other financial assets		0
Receivables	[2],[3]	0
With Specified Maturity Non-Due [Member] | During 2019 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			8,436
Receivables	[2],[3]		17,624
With Specified Maturity Non-Due [Member] | During 2020 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			4,954
Receivables	[2],[3]		0
With Specified Maturity Non-Due [Member] | During 2021 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			4,494
Receivables	[2],[3]		0
With Specified Maturity Non-Due [Member] | During 2022 [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			2,822
Receivables	[2],[3]		0
With Specified Maturity Non-Due [Member] | From 2023 onwards [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents			0
Other financial assets			663
Receivables	[2],[3]		0
With Specified Maturity [Member]
Maturities of financial assets [Abstract]
Cash and cash equivalents		2,159,302	973,646
Other financial assets		232,746	2,480,638
Receivables	[2],[3]	$ 3,677,081	$ 3,290,810
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)
[2]	Includes financial assets recorded in trade receivables and other receivables.
[3]	The total amount of the receivables without specified maturity is recorded in Non-current assets.

FINANCIAL RISK MANAGEMENT, Liqu

FINANCIAL RISK MANAGEMENT, Liquidity Risk (Details) - ARS ($) $ in Thousands	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Maturities of financial liabilities [Abstract]
Loans	$ 20,597,052	[1]	$ 6,642,620	[1]	$ 7,217,464
Liquidity Risk [Member]
Maturities of financial liabilities [Abstract]
Loans	27,120,439		6,036,902
Other financial liabilities	3,479,326		2,537,203
Finance leases	2,199,572		1,812,480
Liquidity Risk [Member] | Without Specified Maturity [Member]
Maturities of financial liabilities [Abstract]
Loans	0		0
Other financial liabilities	0		0
Finance leases	0		0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member]
Maturities of financial liabilities [Abstract]
Loans	0		0
Other financial liabilities	104,841		111,364
Finance leases	56,891		41,545
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | Until 12-31-2017 [Member]
Maturities of financial liabilities [Abstract]
Loans	0
Other financial liabilities	103,597
Finance leases	0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 01-01-18 to 03-31-18 [Member]
Maturities of financial liabilities [Abstract]
Loans	0
Other financial liabilities	311
Finance leases	0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 04-01-18 to 06-30-18 [Member]
Maturities of financial liabilities [Abstract]
Loans	0
Other financial liabilities	311
Finance leases	0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 07-01-18 to 09-30-18 [Member]
Maturities of financial liabilities [Abstract]
Loans	0
Other financial liabilities	311
Finance leases	0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 10-01-18 to 12-31-18 [Member]
Maturities of financial liabilities [Abstract]
Loans	0
Other financial liabilities	311
Finance leases	56,891
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | Until 12-31-2016 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			109,528
Finance leases			0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 01-01-17 to 03-31-17 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			459
Finance leases			0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 04-01-17 to 06-30-17 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			459
Finance leases			0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 07-01-17 to 09-30-17 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			459
Finance leases			0
Liquidity Risk [Member] | With Specified Maturity Over Due [Member] | From 10-01-17 to 12-31-17 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			459
Finance leases			41,545
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member]
Maturities of financial liabilities [Abstract]
Loans	27,120,439		6,036,902
Other financial liabilities	3,374,485		2,425,839
Finance leases	2,142,681		1,770,935
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 01-01-19 to 03-31-19 [Member]
Maturities of financial liabilities [Abstract]
Loans	0
Other financial liabilities	3,352,746
Finance leases	70,499
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 04-01-19 to 06-30-19 [Member]
Maturities of financial liabilities [Abstract]
Loans	636,188
Other financial liabilities	21,739
Finance leases	70,499
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 07-01-19 to 09-30-19 [Member]
Maturities of financial liabilities [Abstract]
Loans	0
Other financial liabilities	0
Finance leases	70,499
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 10-01-19 to 12-31-19 [Member]
Maturities of financial liabilities [Abstract]
Loans	636,188
Other financial liabilities	0
Finance leases	70,499
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 01-01-18 to 03-31-18 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			2,300,495
Finance leases			51,490
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 04-01-18 to 06-30-18 [Member]
Maturities of financial liabilities [Abstract]
Loans			2,012,300
Other financial liabilities			125,344
Finance leases			51,490
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 07-01-18 to 09-30-18 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			0
Finance leases			51,490
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 10-01-18 to 12-31-18 [Member]
Maturities of financial liabilities [Abstract]
Loans			169,249
Other financial liabilities			0
Finance leases			51,490
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2020 [Member]
Maturities of financial liabilities [Abstract]
Loans	1,272,375
Other financial liabilities	0
Finance leases	282,034
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2021 [Member]
Maturities of financial liabilities [Abstract]
Loans	1,272,375
Other financial liabilities	0
Finance leases	282,034
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2022 [Member]
Maturities of financial liabilities [Abstract]
Loans	1,272,375
Other financial liabilities	0
Finance leases	282,034
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2023 [Member]
Maturities of financial liabilities [Abstract]
Loans	1,272,375
Other financial liabilities	0
Finance leases	282,034
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 2024 onwards [Member]
Maturities of financial liabilities [Abstract]
Loans	20,758,563
Other financial liabilities	0
Finance leases	732,549
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2019 [Member]
Maturities of financial liabilities [Abstract]
Loans			2,012,300
Other financial liabilities			0
Finance leases			205,985
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2020 [Member]
Maturities of financial liabilities [Abstract]
Loans			1,843,053
Other financial liabilities			0
Finance leases			205,985
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2021 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			0
Finance leases			205,985
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | During 2022 [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			0
Finance leases			205,985
Liquidity Risk [Member] | With Specified Maturity Non-Due [Member] | From 2023 onwards [Member]
Maturities of financial liabilities [Abstract]
Loans			0
Other financial liabilities			0
Finance leases			741,035
Liquidity Risk [Member] | With Specified Maturity [Member]
Maturities of financial liabilities [Abstract]
Loans	27,120,439		6,036,902
Other financial liabilities	3,479,326		2,537,203
Finance leases	$ 2,199,572		$ 1,812,480
[1]	Issuance expenses net for Ps. 120,420 and Ps. 12,584 as of December 31, 2018 and 2017, respectively.

FINANCIAL RISK MANAGEMENT, Capi

FINANCIAL RISK MANAGEMENT, Capital Risk Management (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	[2]
FINANCIAL RISK MANAGEMENT [Abstract]
Total debt (Note 13)	$ 20,597,052	[1]	$ 6,642,620	[1]	$ 7,217,464
Total Equity	30,945,305		25,279,589	[2]	$ 19,528,403	[2]	$ 18,649,007
Total Capital	$ 51,542,357		$ 31,922,209
Gearing Ratio	0.40%		0.21%
[1]	Issuance expenses net for Ps. 120,420 and Ps. 12,584 as of December 31, 2018 and 2017, respectively.
[2]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

FINANCIAL RISK MANAGEMENT, Fina

FINANCIAL RISK MANAGEMENT, Financial Instrument Categories (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS [Abstract]
Total current assets	$ 20,407,651	$ 9,648,912
NON-CURRENT ASSETS [Abstract]
Total non-current assets	14,949	39,968
Total assets	20,422,600	9,688,880
CURRENT LIABILITIES [Abstract]
Total current liabilities	3,924,898	4,440,851
NON-CURRENT LIABILITIES [Abstract]
Total non-current liabilities	20,154,216	4,680,011
Total liabilities	24,079,114	9,120,862
Trade Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	3,092,037	2,145,738
Loans [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	442,836	1,962,609
Payroll and Social Security Taxes Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	309,351	282,973
Other Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	80,674	49,531
Loans [Member]
NON-CURRENT LIABILITIES [Abstract]
Total non-current liabilities	20,154,216	4,680,011
Financial Liabilities at Fair Value [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	0	0
NON-CURRENT LIABILITIES [Abstract]
Total non-current liabilities	0	0
Total liabilities	0	0
Financial Liabilities at Fair Value [Member] | Trade Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	0	0
Financial Liabilities at Fair Value [Member] | Loans [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	0	0
Financial Liabilities at Fair Value [Member] | Payroll and Social Security Taxes Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	0	0
Financial Liabilities at Fair Value [Member] | Other Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	0	0
Financial Liabilities at Fair Value [Member] | Loans [Member]
NON-CURRENT LIABILITIES [Abstract]
Total non-current liabilities	0	0
Other Financial Liabilities [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	3,924,898	4,440,851
NON-CURRENT LIABILITIES [Abstract]
Total non-current liabilities	20,154,216	4,680,011
Total liabilities	24,079,114	9,120,862
Other Financial Liabilities [Member] | Trade Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	3,092,037	2,145,738
Other Financial Liabilities [Member] | Loans [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	442,836	1,962,609
Other Financial Liabilities [Member] | Payroll and Social Security Taxes Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	309,351	282,973
Other Financial Liabilities [Member] | Other Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities	80,674	49,531
Other Financial Liabilities [Member] | Loans [Member]
NON-CURRENT LIABILITIES [Abstract]
Total non-current liabilities	20,154,216	4,680,011
Trade Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets	3,114,499	3,002,432
NON-CURRENT ASSETS [Abstract]
Total non-current assets		4,511
Other Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets	424,339	270,464
NON-CURRENT ASSETS [Abstract]
Total non-current assets	6,189	14,088
Derivative Financial Instruments [Member]
CURRENT ASSETS [Abstract]
Total current assets	218,272
Other Financial Assets at Amortized Cost [Member]
CURRENT ASSETS [Abstract]
Total current assets	5,714	2,134,111
NON-CURRENT ASSETS [Abstract]
Total non-current assets	8,760
Other Financial Assets at Fair Value Through Profit or Loss [Member]
CURRENT ASSETS [Abstract]
Total current assets		325,158
NON-CURRENT ASSETS [Abstract]
Total non-current assets		21,369
Cash and Cash Equivalents [Member]
CURRENT ASSETS [Abstract]
Total current assets	16,644,827	3,916,747
Financial Assets at Fair Value [Member]
CURRENT ASSETS [Abstract]
Total current assets	2,379,439	2,285,854
NON-CURRENT ASSETS [Abstract]
Total non-current assets	0	0
Total assets	2,379,439	2,285,854
Financial Assets at Fair Value [Member] | Trade Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets	0	0
NON-CURRENT ASSETS [Abstract]
Total non-current assets		0
Financial Assets at Fair Value [Member] | Other Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets	0	0
NON-CURRENT ASSETS [Abstract]
Total non-current assets	0	0
Financial Assets at Fair Value [Member] | Derivative Financial Instruments [Member]
CURRENT ASSETS [Abstract]
Total current assets	218,272
Financial Assets at Fair Value [Member] | Other Financial Assets at Amortized Cost [Member]
CURRENT ASSETS [Abstract]
Total current assets	0	0
NON-CURRENT ASSETS [Abstract]
Total non-current assets	0
Financial Assets at Fair Value [Member] | Other Financial Assets at Fair Value Through Profit or Loss [Member]
CURRENT ASSETS [Abstract]
Total current assets		325,158
NON-CURRENT ASSETS [Abstract]
Total non-current assets		0
Financial Assets at Fair Value [Member] | Cash and Cash Equivalents [Member]
CURRENT ASSETS [Abstract]
Total current assets	2,161,167	1,960,696
Financial Assets Held to Maturity [Member]
CURRENT ASSETS [Abstract]
Total current assets	18,028,212	2,123,611
NON-CURRENT ASSETS [Abstract]
Total non-current assets	14,949	0
Total assets	18,043,161	2,123,611
Financial Assets Held to Maturity [Member] | Trade Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets	3,114,499	0
NON-CURRENT ASSETS [Abstract]
Total non-current assets		0
Financial Assets Held to Maturity [Member] | Other Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets	424,339	0
NON-CURRENT ASSETS [Abstract]
Total non-current assets	6,189	0
Financial Assets Held to Maturity [Member] | Derivative Financial Instruments [Member]
CURRENT ASSETS [Abstract]
Total current assets	0
Financial Assets Held to Maturity [Member] | Other Financial Assets at Amortized Cost [Member]
CURRENT ASSETS [Abstract]
Total current assets	5,714	2,123,611
NON-CURRENT ASSETS [Abstract]
Total non-current assets	8,760
Financial Assets Held to Maturity [Member] | Other Financial Assets at Fair Value Through Profit or Loss [Member]
CURRENT ASSETS [Abstract]
Total current assets		0
NON-CURRENT ASSETS [Abstract]
Total non-current assets		0
Financial Assets Held to Maturity [Member] | Cash and Cash Equivalents [Member]
CURRENT ASSETS [Abstract]
Total current assets	$ 14,483,660	0
Loans and Other Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets		5,239,447
NON-CURRENT ASSETS [Abstract]
Total non-current assets		39,968
Total assets		5,279,415
Loans and Other Receivables [Member] | Trade Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets		3,002,432
NON-CURRENT ASSETS [Abstract]
Total non-current assets		4,511
Loans and Other Receivables [Member] | Other Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets		270,464
NON-CURRENT ASSETS [Abstract]
Total non-current assets		14,088
Loans and Other Receivables [Member] | Other Financial Assets at Amortized Cost [Member]
CURRENT ASSETS [Abstract]
Total current assets		10,500
Loans and Other Receivables [Member] | Other Financial Assets at Fair Value Through Profit or Loss [Member]
CURRENT ASSETS [Abstract]
Total current assets		0
NON-CURRENT ASSETS [Abstract]
Total non-current assets		21,369
Loans and Other Receivables [Member] | Cash and Cash Equivalents [Member]
CURRENT ASSETS [Abstract]
Total current assets		$ 1,956,051

FINANCIAL RISK MANAGEMENT, Fair

FINANCIAL RISK MANAGEMENT, Fair Value Measurement Hierarchy and Estimates (Details) - ARS ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial assets at fair value [Abstract]
Derivative financial instruments	$ 218,272	$ 0	[1]
Other current financial assets at fair value through profit or loss	0	325,158	[1]
Financial liabilities at carrying amount and estimated fair value [Abstract]
Carrying amount	24,079,114	9,120,862
2018 note [Member]
Financial liabilities at carrying amount and estimated fair value [Abstract]
Carrying amount	18,941,643
Fair Value	17,200,060
Fair Value [Member]
Financial assets at fair value [Abstract]
Cash and cash equivalents	2,161,167	1,960,696
Derivative financial instruments	218,272
Other current financial assets at fair value through profit or loss		325,158
Total	2,379,439	2,285,854
Fair Value [Member] | Level 1 [Member]
Financial assets at fair value [Abstract]
Cash and cash equivalents	2,161,167	1,960,696
Derivative financial instruments	0
Other current financial assets at fair value through profit or loss		325,158
Total	2,161,167	2,285,854
Fair Value [Member] | Level 2 [Member]
Financial assets at fair value [Abstract]
Cash and cash equivalents	0	0
Derivative financial instruments	218,272
Other current financial assets at fair value through profit or loss		0
Total	218,272	0
Fair Value [Member] | Level 3 [Member]
Financial assets at fair value [Abstract]
Cash and cash equivalents	0	0
Derivative financial instruments	0
Other current financial assets at fair value through profit or loss		0
Total	$ 0	$ 0
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

REGULATORY FRAMEWORK, General F

REGULATORY FRAMEWORK, General Framework of the Natural Gas Transportation Segment (Details) $ in Thousands

12 Months Ended

Dec. 31, 2018ARS ($)

Apr. 01, 2019

Oct. 02, 2018

Sep. 04, 2018

Apr. 01, 2018

Dec. 01, 2017

Apr. 02, 2017

Mar. 30, 2017

Apr. 02, 2016

Jun. 05, 2015

Aug. 01, 2014

Jun. 01, 2014

Apr. 01, 2014

General aspects [Abstract]

Original license period

35 years

License period, renewal

10 years

License period, after renewal

45 years

Tariff situation [Abstract]

Natural gas transportation tariffs period, condition one

semi-annually

Natural gas transportation tariffs period, condition two

5 years

Conversion rate of exchange for tariffs

1

Number of years for negotiations under transitional agreement

17 years

Transitional Agreement [Abstract]

Percentage of increase in tariff

19.70%

30.00%

20.00%

14.00%

8.00%

Percentage of increase in tariff on service for natural gas transportation

81.10%

64.20%

214.20%

44.30%

Percentage of increase in tariff on access and use

29.70%

37.00%

73.20%

Percentage of tariff increase on public service of Natural Gas Transportation and CAU

50.00%

200.10%

Investment plan period

5 years

Five Year Plan investment amount

$ 6,786,543

Subsequent Event [Member]

Transitional Agreement [Abstract]

Percentage of increase in tariff

26.00%

REGULATORY FRAMEWORK, Regulator

REGULATORY FRAMEWORK, Regulatory Framework for Non-Regulated Segments (Details)	Jan. 28, 2019ARS ($)	Mar. 27, 2018ARS ($)	Dec. 01, 2017ARS ($)	Apr. 01, 2017ARS ($)	Dec. 01, 2011$ / m³	Nov. 30, 2011$ / m³	Mar. 31, 2017ARS ($)	Dec. 31, 2018ARS ($)$ / m³	Dec. 31, 2017ARS ($)	Dec. 31, 2016ARS ($)	Sep. 03, 2018USD ($)
Domestic market [Abstract]
Increase in price of household bottles per ton							$ 650,000			$ 650,000
Increase in price of propane gas per ton									$ 1,267,000
Increase in price of propane gas per ton depending on customer									2,832,000
Subsidies booked								$ 406,727,000	347,655,000	314,028,000
Subsidies receivable from government								292,866,000	255,886,000
Compensation received from government per ton								$ 550,000
Foreign market [Abstract]
Capped amount of each dollar of the tax base or the official FOB price											$ 4
Tariff charge paid (per cubic meter) | $ / m³								0.0492
Tariff charge (per cubic meter) | $ / m³					0.405	0.049
Production and Commercialization of Liquids [Member]
Domestic market [Abstract]
Subsidies booked								$ 406,727,000	347,655,000	$ 314,028,000
Butane [Member]
Domestic market [Abstract]
Increase in price of household bottles per ton		$ 5,416,000	$ 4,302,000	$ 2,568,000
Foreign market [Abstract]
Export duty percentage											12.00%
Butane [Member] | Subsequent events [Member]
Domestic market [Abstract]
Increase in price of household bottles per ton	$ 9,154,000
Propane [Member]
Domestic market [Abstract]
Increase in price of household bottles per ton		$ 5,502,000	$ 4,290,000	$ 2,410,000
Increase in price of propane gas per ton									1,941,200
Increase in price of propane gas per ton depending on customer									$ 3,694,000
Foreign market [Abstract]
Export duty percentage											12.00%
Propane [Member] | Subsequent events [Member]
Domestic market [Abstract]
Increase in price of household bottles per ton	$ 9,042,000
Natural Gasoline [Member]
Foreign market [Abstract]
Export duty percentage											12.00%

ASSETS AND LIABILITIES IN FOR_3

ASSETS AND LIABILITIES IN FORREIGN CURRENCY (Details) $ in Thousands, $ in Thousands		Dec. 31, 2018ARS ($)$ / $	Dec. 31, 2018USD ($)$ / $	Dec. 31, 2017ARS ($)	Dec. 31, 2017USD ($)
CURRENT ASSETS [Abstract]
Total current assets		$ 20,407,651		$ 9,648,912
NON CURRENT ASSETS [Abstract]
Total non-current assets		14,949		39,968
TOTAL ASSETS		20,422,600		9,688,880
CURRENT LIABILITIES [Abstract]
Total current liabilities		3,924,898		4,440,851
NON CURRENT LIABILITIES [Abstract]
Total non-current liabilities		20,154,216		4,680,011
TOTAL LIABILITIES		$ 24,079,114		9,120,862
Exchange rate (in Ps. per dollars) | $ / $		37.7	37.7
Trade Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities		$ 3,092,037		2,145,738
Loans [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities		442,836		1,962,609
Loans [Member]
NON CURRENT LIABILITIES [Abstract]
Total non-current liabilities		20,154,216		4,680,011
Cash and Cash Equivalents [Member]
CURRENT ASSETS [Abstract]
Total current assets		16,644,827		3,916,747
Other Financial Assets at Amortized Cost [Member]
CURRENT ASSETS [Abstract]
Total current assets		5,714		2,134,111
NON CURRENT ASSETS [Abstract]
Total non-current assets		8,760
Other Financial Assets at Fair Value Through Profit or Loss [Member]
CURRENT ASSETS [Abstract]
Total current assets				325,158
NON CURRENT ASSETS [Abstract]
Total non-current assets				21,369
Trade receivables [member]
CURRENT ASSETS [Abstract]
Total current assets		3,114,499		3,002,432
NON CURRENT ASSETS [Abstract]
Total non-current assets				4,511
Other Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets		424,339		270,464
NON CURRENT ASSETS [Abstract]
Total non-current assets		6,189		14,088
Foreign Currency [member]
CURRENT ASSETS [Abstract]
Total current assets		14,788,854		5,274,679
NON CURRENT ASSETS [Abstract]
Total non-current assets		0		4,511
TOTAL ASSETS		14,788,854		5,279,190
CURRENT LIABILITIES [Abstract]
Total current liabilities		2,033,173		3,200,771
NON CURRENT LIABILITIES [Abstract]
Total non-current liabilities		20,154,216		4,680,011
TOTAL LIABILITIES		22,187,389		7,880,782
Foreign Currency [member] | Trade Payables [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities		$ 1,590,337	$ 42,184	1,238,162	$ 44,882
NON CURRENT LIABILITIES [Abstract]
Exchange rate (in Ps. per dollars) | $ / $	[1]	37.7	37.7
Foreign Currency [member] | Loans [Member]
CURRENT LIABILITIES [Abstract]
Total current liabilities		$ 442,836	$ 11,746	1,962,609	71,278
NON CURRENT LIABILITIES [Abstract]
Exchange rate (in Ps. per dollars) | $ / $	[1]	37.7	37.7
Foreign Currency [member] | Loans [Member]
NON CURRENT LIABILITIES [Abstract]
Total non-current liabilities		$ 20,154,216	$ 534,595	4,680,011	169,969
Exchange rate (in Ps. per dollars) | $ / $	[1]	37.7	37.7
Foreign Currency [member] | Cash and Cash Equivalents [Member]
CURRENT ASSETS [Abstract]
Total current assets		$ 13,538,138	$ 361,017	1,937,122	70,732
NON CURRENT LIABILITIES [Abstract]
Exchange rate (in Ps. per dollars) | $ / $	[2]	37.5	37.5
Foreign Currency [member] | Other Financial Assets at Amortized Cost [Member]
CURRENT ASSETS [Abstract]
Total current assets		$ 5,714	$ 152	1,361,756	49,723
NON CURRENT LIABILITIES [Abstract]
Exchange rate (in Ps. per dollars) | $ / $	[2]	37.5	37.5
Foreign Currency [member] | Other Financial Assets at Fair Value Through Profit or Loss [Member]
CURRENT ASSETS [Abstract]
Total current assets		$ 0	$ 0	325,158	11,873
Foreign Currency [member] | Trade receivables [member]
CURRENT ASSETS [Abstract]
Total current assets		1,181,514	31,507	1,584,011	57,838
NON CURRENT ASSETS [Abstract]
Total non-current assets		$ 0	$ 0	4,511	165
NON CURRENT LIABILITIES [Abstract]
Exchange rate (in Ps. per dollars) | $ / $	[2]	37.5	37.5
Foreign Currency [member] | Other Receivables [Member]
CURRENT ASSETS [Abstract]
Total current assets		$ 63,488	$ 1,693	$ 66,632	$ 2,433
NON CURRENT LIABILITIES [Abstract]
Exchange rate (in Ps. per dollars) | $ / $	[2]	37.5	37.5
[1]	Sell exchange rate at the end of fiscal year
[2]	Buy exchange rate at the end of fiscal year

COMMON STOCK AND DIVIDENDS (Det

COMMON STOCK AND DIVIDENDS (Details)	12 Months Ended
	Dec. 31, 2018Vote$ / sharesshares	Dec. 31, 2018$ / sharesshares	Dec. 31, 2017shares
Common stock structure and shares [Abstract]
Outstanding shares (in shares)	780,894,503	780,894,503
Number of shares represents for each share on New York Stock Exchange (in shares)	5
Class "A" [Member]
Common stock structure and shares [Abstract]
Outstanding shares (in shares)	405,192,594	405,192,594
Face value common shares class (in dollars per share) | $ / shares		$ 1
Number of votes for common stock | Vote	1
Class "B" [Member]
Common stock structure and shares [Abstract]
Outstanding shares (in shares)	375,701,909	375,701,909
Face value common shares class (in dollars per share) | $ / shares		$ 1
Number of votes for common stock | Vote	1
Common Stock [Member]
Common stock structure and shares [Abstract]
Shares issued (in shares)	794,495,283	794,495,283
Common Stock [Member] | Class "A" [Member]
Common stock structure and shares [Abstract]
Shares issued (in shares)	405,192,594	405,192,594
Common Stock [Member] | Class "B" [Member]
Common stock structure and shares [Abstract]
Shares issued (in shares)	389,302,689	389,302,689
Treasury Shares [Member]
Common stock structure and shares [Abstract]
Shares issued (in shares)	13,600,780	13,600,780	0
Face value common shares class (in dollars per share) | $ / shares	$ 1
Treasury Shares [Member] | Class "A" [Member]
Common stock structure and shares [Abstract]
Shares issued (in shares)	0	0
Treasury Shares [Member] | Class "B" [Member]
Common stock structure and shares [Abstract]
Shares issued (in shares)	13,600,780	13,600,780

COMMON STOCK AND DIVIDENDS, Div

COMMON STOCK AND DIVIDENDS, Dividends distribution (Details) - ARS ($) $ / shares in Units, $ in Thousands	Sep. 06, 2018	Aug. 08, 2018	Jul. 06, 2018
COMMON STOCK AND DIVIDENDS [Abstract]
Amount	$ 1,754,326	$ 1,449,300	$ 1,125,562
Amount per share (in dollars per share)	$ 2.2081	$ 1.8242	$ 1.4167

COMMON STOCK AND DIVIDENDS, Acq

COMMON STOCK AND DIVIDENDS, Acquisition of treasury shares (Details) - ARS ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Sep. 06, 2018	Mar. 31, 2018	Dec. 31, 2017
Acquisition of treasury shares [Abstract]
Maximum amount invested for Shares Repurchase Program		$ 1,800,000	$ 1,700,000
Shares Repurchase Program term	180 days
Shares Repurchase Program expiration date	Mar. 5, 2019
Treasury Shares [Member]
Acquisition of treasury shares [Abstract]
Shares issued (in shares)	13,600,780			0
Percentage of total common stock representing shares repurchased	1.71%
Acquisition cost restated to inflation amount	$ 1,420,926

LEGAL CLAIMS AND OTHER MATTERS

LEGAL CLAIMS AND OTHER MATTERS (Details) $ in Millions, $ in Millions

Jun. 14, 2018USD ($)

May 28, 2018USD ($)

Mar. 15, 2017USD ($)

May 08, 2015Contract

Oct. 09, 2008

Dec. 31, 2018USD ($)

Dec. 31, 2017ARS ($)

Dec. 31, 2016ARS ($)

Jun. 30, 2011ARS ($)

Dec. 31, 2018ARS ($)

Mar. 31, 2017ARS ($)

May 24, 2013ARS ($)

LEGAL CLAIMS AND OTHER MATTERS [Abstract]

Payment for claims to provincial agencies

$ 148.5

$ 27.6

Provisions for contingency

279.6

$ 308.4

Validity period of precautionary measure

6 months

Increase in tariff percentage

20.00%

Receivables from income taxes and value added tax

$ 105

$ 69.4

Claim amount for the omission as agent of withholding and collection of turnover tax

$ 4.9

Canceled partial debt claim amount

$ 2.9

Number of natural gas contracts executed | Contract

3

Claim amount due to lower allocation of products obtained

$ 163

Adjusted of claim

$ 306.3

Nominal damages

134

Interest on nominal damages

$ 172.3

Damages to claimants

$ 19

Payment for damages

$ 21.3

Provision for other matters

$ 9.6

$ 59.7

BALANCES AND TRANSACTIONS WIT_3

BALANCES AND TRANSACTIONS WITH RELATED COMPANIES (Details) $ in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2018ARS ($)		Dec. 31, 2017ARS ($)		Dec. 31, 2016ARS ($)	Dec. 31, 2018USD ($)	Aug. 08, 2017ARS ($)
Technical, financial and operational assistance agreement [abstract]
Compensation for key management member		$ 83,820		$ 85,648		$ 79,094
Balances and transactions with related parties [Abstract]
Accounts receivable		348,112		36,437
Accounts payable		1,856,506		1,467,632
Costs [Abstract]
Gas purchase and others		631,016		302,488		559,268
Compensation for technical assistance		1,317,176		577,187		329,826
Revenue for administrative services		146		2,269		244
Financial Results [Abstract]
Interest expenses		125,467		107,731		50,145
Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		539,749		76,078		73,187
Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		1,323		93,573		768,340
Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		259,810		125,761		362,636
Compania Mega S.A. [Member]
Costs [Abstract]
Gas purchase and others						0
Compensation for technical assistance						0
Revenue for administrative services						0
Financial Results [Abstract]
Interest expenses						0
Compania Mega S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						3,325
Compania Mega S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						176,841
Compania Mega S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						35
Braskem [Member]
Costs [Abstract]
Compensation for technical assistance						0
Revenue for administrative services						0
Financial Results [Abstract]
Interest expenses						0
Braskem [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
Braskem [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						42,611
Braskem [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
Costs [Abstract]
Gas purchase and others						4,361
Petroleo Brasileiro [Member]
Costs [Abstract]
Gas purchase and others						0
Compensation for technical assistance						0
Revenue for administrative services						0
Financial Results [Abstract]
Interest expenses						0
Petroleo Brasileiro [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
Petroleo Brasileiro [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						546,476
Petroleo Brasileiro [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
Refinor S.A. [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		0		0
Accounts payable		0		5,218
Costs [Abstract]
Gas purchase and others				5,350
Compensation for technical assistance				0
Revenue for administrative services				0
Financial Results [Abstract]
Interest expenses				0
Refinor S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
Refinor S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
Refinor S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
Petrolera Pampa S.A. [Member]
Costs [Abstract]
Gas purchase and others				40,344		333,944
Compensation for technical assistance				0		0
Revenue for administrative services				0		0
Financial Results [Abstract]
Interest expenses				0		0
Petrolera Pampa S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0		0
Petrolera Pampa S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0		0
Petrolera Pampa S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0		0
SACDE [Member]
Technical, financial and operational assistance agreement [abstract]
Amount received for services		263,580
Balances and transactions with related parties [Abstract]
Accounts receivable		214,148		0
Accounts payable		0		0
Petrolera Entre Lomas S.A. [Member]
Costs [Abstract]
Gas purchase and others		2,017	[1]	17,801		50,356
Compensation for technical assistance		0	[1]	0		0
Revenue for administrative services		0	[1]	0		0
Financial Results [Abstract]
Interest expenses		0	[1]	0		0
Petrolera Entre Lomas S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0	[1]	0		0
Petrolera Entre Lomas S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0	[1]	0		0
Petrolera Entre Lomas S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0	[1]	0		350
Pampa Comercializadora S.A. [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		7,113		2,779
Accounts payable		0		0
Costs [Abstract]
Gas purchase and others		0		0		0
Compensation for technical assistance		0		0		0
Revenue for administrative services		0		0		0
Financial Results [Abstract]
Interest expenses		0		0		0
Pampa Comercializadora S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		26,869		10,775		7,009
Pampa Comercializadora S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0		0		0
Pampa Comercializadora S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0		0		0
Oleoductos del Valle S.A. [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		3,131		1,975
Accounts payable		0		0
Costs [Abstract]
Gas purchase and others		0				0
Compensation for technical assistance		0				0
Revenue for administrative services		0				0
Financial Results [Abstract]
Interest expenses		0				0
Oleoductos del Valle S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		6,149				4,715
Oleoductos del Valle S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0				0
Oleoductos del Valle S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		8,277				0
Petrouruguay S.A. [Member]
Costs [Abstract]
Gas purchase and others						0
Compensation for technical assistance						0
Revenue for administrative services						0
Financial Results [Abstract]
Interest expenses						0
Petrouruguay S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						722
Petrouruguay S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						95
Petrouruguay S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
WEB S.A. [Member]
Costs [Abstract]
Gas purchase and others						7,262
Compensation for technical assistance						0
Revenue for administrative services						0
Financial Results [Abstract]
Interest expenses						0
WEB S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						220
WEB S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
WEB S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
Central Piedra Buena S.A. [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		25,463		7,661
Accounts payable		0		0
Costs [Abstract]
Gas purchase and others		0
Compensation for technical assistance		0
Revenue for administrative services		0
Financial Results [Abstract]
Interest expenses		0
Central Piedra Buena S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		67,175
Central Piedra Buena S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0
Central Piedra Buena S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0
Central Temica Loma La Lata S.A. [Member]
Costs [Abstract]
Gas purchase and others				0
Compensation for technical assistance				0
Revenue for administrative services				0
Financial Results [Abstract]
Interest expenses				0
Central Temica Loma La Lata S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
Central Temica Loma La Lata S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
Central Temica Loma La Lata S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				389
Central Termica Piedrabuena S.A. [Member]
Costs [Abstract]
Gas purchase and others						0
Compensation for technical assistance						0
Revenue for administrative services						0
Financial Results [Abstract]
Interest expenses						0
Central Termica Piedrabuena S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						14,162
Central Termica Piedrabuena S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
Central Termica Piedrabuena S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues						0
Transener S.A. [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		91		44
Accounts payable		0		0
Costs [Abstract]
Gas purchase and others		0
Compensation for technical assistance		0
Revenue for administrative services		0
Financial Results [Abstract]
Interest expenses		0
Transener S.A. [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0
Transener S.A. [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0
Transener S.A. [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		12,014
Experta ART [Member]
Costs [Abstract]
Gas purchase and others		11,910		11,949		0
Compensation for technical assistance		0		0		0
Revenue for administrative services		0		0		0
Financial Results [Abstract]
Interest expenses		0		0		0
Experta ART [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0		0		0
Experta ART [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0		0		0
Experta ART [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0		0		0
Link [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		6,482		768
Accounts payable		0		0
Costs [Abstract]
Gas purchase and others		0				0
Compensation for technical assistance		0				0
Revenue for administrative services		0				0
Financial Results [Abstract]
Interest expenses		0				0
Link [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0				0
Link [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0				0
Link [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		8,589				7,787
EGS [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		0		0
Accounts payable		0		679
TGU [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		0		0
Accounts payable		$ 6,001		4,383
CTG [Member]
Technical, financial and operational assistance agreement [abstract]
Cash payments for acquisition								$ 148
Pampa Energia [Member]
Technical, financial and operational assistance agreement [abstract]
Technical assistance agreement term renewal		3 years
Percentage of annual comprehensive profits for providing operation and maintenance services		7.00%
Balances and transactions with related parties [Abstract]
Accounts receivable	[2]	$ 91,684		23,152
Accounts payable		1,850,505	[2]	1,457,352	[2]		$ 3
Financial lease		1,655,409		1,316,061
Costs [Abstract]
Gas purchase and others		617,089		227,044		163,345
Compensation for technical assistance		1,317,176		577,187		329,826
Revenue for administrative services		0		0		0
Financial Results [Abstract]
Interest expenses		125,467		107,731		50,145
Pampa Energia [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		439,556		44,683		43,034
Pampa Energia [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		1,323		93,573		2,317
Pampa Energia [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		230,930		116,186		354,464
UT [Member]
Costs [Abstract]
Gas purchase and others				0
Compensation for technical assistance				0
Revenue for administrative services				2,115
Financial Results [Abstract]
Interest expenses				0
UT [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
UT [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
UT [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues				0
CIESA [Member]
Balances and transactions with related parties [Abstract]
Accounts receivable		0		58
Accounts payable		0		0
Costs [Abstract]
Gas purchase and others		0		0		0
Compensation for technical assistance		0		0		0
Revenue for administrative services		146		154		244
Financial Results [Abstract]
Interest expenses		0		0		0
CIESA [Member] | Natural Gas Transportation [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0		0		0
CIESA [Member] | Production and Commercialization of Liquids [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		0		0		0
CIESA [Member] | Other Services [Member]
Detail of Significant Transactions with Related Parties [abstract]
Revenues		$ 0		$ 0		$ 0
[1]	As from April 2018, Petrolera Entre Lomas S.A is no longer a related party
[2]	Accounts payable includes Ps. 1,655,409 and Ps. 1,316,061 corresponding to the financial leasing recorded as "Loans" as of December 31, 2018 and 2017, respectively.

CONTRACTUAL OBLIGATIONS (Detail

CONTRACTUAL OBLIGATIONS (Details) $ in Thousands	Dec. 31, 2018ARS ($)$ / $
Contractual commitments [abstract]
Financial indebtedness	$ 27,120,439	[1]
Purchase obligations	4,836,612	[2]
Financial Leases	2,199,572
Total	$ 34,156,623
Exchange rate (in Ps. per dollars) | $ / $	37.7
Due Less than One Year [Member]
Contractual commitments [abstract]
Financial indebtedness	$ 0	[1]
Purchase obligations	0	[2]
Financial Leases	56,892
Total	56,892
Less than One year [Member]
Contractual commitments [abstract]
Financial indebtedness	1,272,376	[1]
Purchase obligations	3,396,343	[2]
Financial Leases	281,995
Total	4,950,714
1-2 Years [Member]
Contractual commitments [abstract]
Financial indebtedness	3,817,125	[1]
Purchase obligations	1,440,269	[2]
Financial Leases	564,068
Total	5,821,462
3-5 Years [Member]
Contractual commitments [abstract]
Financial indebtedness	2,544,750	[1]
Purchase obligations	0	[2]
Financial Leases	564,050
Total	3,108,800
More than 5 Years [Member]
Contractual commitments [abstract]
Financial indebtedness	19,486,188	[1]
Purchase obligations	0	[2]
Financial Leases	732,567
Total	$ 20,218,755
[1]	Corresponds to the cancellation of principal and interest of the financial indebtedness. For further information, see Note 13.
[2]	Corresponds to purchase of natural gas contracts for the processing of liquids.

ASSOCIATES AND JOINT ARRANGEM_2

ASSOCIATES AND JOINT ARRANGEMENTS (Details) $ in Thousands	Oct. 13, 2016ARS ($)	Dec. 17, 2013USD ($)	Dec. 31, 2018ARS ($)	Dec. 31, 2017ARS ($)	[1]	Dec. 31, 2016ARS ($)	[1]
Information about associates and arrangements [Abstract]
Purchase of fixed assets			$ 8,123,664	$ 1,941,265		$ 1,017,590
UT [Member]
Information about associates and arrangements [Abstract]
Maximum execution period of the UT works			365 days
Guarantee period from the provisional reception of the UT Works			18 months
Link [Member]
Information about associates and arrangements [Abstract]
Percentage of ownership			49.00%
Link [Member] | Dinarel S.A. [Member]
Information about associates and arrangements [Abstract]
Percentage of ownership			51.00%
TGU [Member]
Information about associates and arrangements [Abstract]
Percentage of ownership			49.00%
TGU [Member] | Pampa Energia [Member]
Information about associates and arrangements [Abstract]
Percentage of ownership			51.00%
EGS [Member]
Information about associates and arrangements [Abstract]
Percentage of ownership			49.00%
Purchase of fixed assets		$ 350,000
Distribution of dividend in kind	$ 8,679
EGS [Member] | TGU [Member]
Information about associates and arrangements [Abstract]
Percentage of ownership			51.00%
[1]	The Company has applied IFRS 15 and IFRS 9 for the first time on January 1, 2018. In accordance with the transition methods chosen, the comparative information has not been modified. See Note 4.a)

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - ARS ($) $ / shares in Units, $ in Thousands	Apr. 25, 2019	Apr. 11, 2019	Mar. 27, 2019	Sep. 06, 2018	Aug. 08, 2018	Jul. 06, 2018	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Subsequent Event [Abstract]
Maximum amount approved for treasury shares repurchase program				$ 1,800,000				$ 1,700,000
Shares Repurchase Program term							180 days
Cash dividends (in pesos per share)				$ 2.2081	$ 1.8242	$ 1.4167
Treasury Shares [Member]
Subsequent Event [Abstract]
Shares issued (in shares)							13,600,780		0
Percentage of total common stock representing shares repurchased							1.71%
Subsequent events [Member]
Subsequent Event [Abstract]
Maximum amount approved for treasury shares repurchase program			$ 1,500,000
Shares Repurchase Program term			180 days
Increase in legal reserve		$ 640,132
Cash dividends		$ 6,942,000
Cash dividends (in pesos per share)		$ 8.89
Voluntary reserve		$ 6,354,164
Percentage of voluntary reserve can be used for future invest, stock buyback and cash dividend payment		80.00%
Cash dividend from voluntary reserve		$ 240,500
Cash dividend from voluntary reserve (in pesos per sare)		$ 0.31
Subsequent events [Member] | Treasury Shares [Member]
Subsequent Event [Abstract]
Shares issued (in shares)	15,310,025
Percentage of total common stock representing shares repurchased	1.93%