TC Pipelines (TCP) 10-Q 7 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Aug. 03, 2015
Document and Entity Information
Entity Registrant Name	TC PIPELINES LP
Entity Central Index Key	1,075,607
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		63,957,751
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Transmission revenues	$ 85	$ 82	$ 172	$ 169
Equity earnings from unconsolidated affiliates (Note 4)	15	18	46	51
Operation and maintenance expenses	(13)	(12)	(24)	(24)
Property taxes	(5)	(6)	(11)	(12)
General and administrative	(1)	(1)	(4)	(3)
Depreciation	(21)	(22)	(42)	(43)
Financial charges and other	(16)	(14)	(29)	(26)
Net income	44	45	108	112
Net income attributable to non-controlling interests		8	7	18
Net income attributable to controlling interests	44	37	101	94
Calculation of net income attributable to common units
Net income attributable to controlling interests	44	37	101	94
Less: Net income allocated to the General Partner, including incentive distributions	2	1	3	2
Common units
Calculation of net income attributable to common units
Net Income allocated to common units (Note 8)	$ 42	$ 36	$ 98	$ 92
Weighted average common units outstanding (millions) - basic (in units)	63.8	62.3	63.7	62.3
Weighted average common units outstanding (millions) - diluted (in units)	63.8	62.3	63.7	62.3
Net income per common unit (Note 8) - basic (in dollars per unit)	$ 0.66	$ 0.58	$ 1.53	$ 1.48
Net income per common unit (Note 8) - diluted (in dollars per unit)	$ 0.66	$ 0.58	$ 1.53	$ 1.48
Common units outstanding, end of period (millions) (in units)	64	62.3	64	62.3

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 44	$ 45	$ 108	$ 112
Other comprehensive income
Change in fair value of cash flow hedges (Note 12)		(1)	(1)	(1)
Comprehensive income	44	44	107	111
Comprehensive income attributable to non-controlling interests		8	7	18
Comprehensive income attributable to controlling interests	$ 44	$ 36	$ 100	$ 93

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 44	$ 26
Accounts receivable and other (Note 13)	33	35
Inventories	7	7
Total current assets	84	68
Investments in unconsolidated affiliates (Note 4)	1,158	1,177
Plant, property and equipment (Net of $774 accumulated depreciation; 2014 - $737	1,946	1,968
Goodwill	130	130
Other assets	9	6
Total assets	3,327	3,349
Current Liabilities
Accounts payable and accrued liabilities	30	23
Accounts payable to affiliates (Note 11)	10	15
Accrued interest	8	4
Short-term loan (Note 5)	170	170
Current portion of long-term debt (Note 5)	14	79
Total current liabilities	232	291
Long-term debt (Note 5)	1,730	1,446
Other liabilities	27	26
Total liabilities	1,989	1,763
Partners' Equity
General partner	29	29
Accumulated other comprehensive loss	(3)	(2)
Controlling interests	1,338	1,352
Non-controlling interests		234
Total partners' equity	1,338	1,586
Total liabilities and partners' equity	3,327	3,349
Common units
Partners' Equity
Limited partner	1,217	$ 1,325
Class B units
Partners' Equity
Limited partner	$ 95

CONSOLIDATED BALANCE SHEET (Par

CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
CONSOLIDATED BALANCE SHEETS
Accumulated depreciation	$ 774	$ 737

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Generated From Operations
Net income	$ 108	$ 112
Depreciation	42	43
Amortization of debt issue costs	1	1
Change in other liabilities		1
Equity allowance for funds used during construction	(1)
Change in operating working capital (Note 10)	1	28
Total cash generated from operations	151	185
Investing Activities
Investment in Great Lakes	(4)	(4)
Adjustment to 2013 acquisition (Note 11)		(25)
Acquisition of the remaining 30 percent interest in GTN (Note 6)	(264)
Capital expenditures	(12)	(5)
Other	(1)	1
Total investing activities	(258)	(18)
Financing Activities
Distributions paid (Note 9)	(110)	(103)
Distributions paid to non-controlling interests	(9)	(29)
ATM Equity issuance, net (Note 7)	26
Equity contribution by the General Partner (Note 6)	2
Long-term debt issued, net of discount	424	15
Long-term debt repaid	(205)	(30)
Debt issuance costs	(3)
Total financing activities	125	(147)
Increase/(decrease) in cash and cash equivalents	18	20
Cash and cash equivalents, beginning of period	26	25
Cash and cash equivalents, end of period	44
Northern Border
Investing Activities
Cumulative distributions in excess of equity earnings	13	8
Great Lakes
Investing Activities
Cumulative distributions in excess of equity earnings	$ 10	$ 7

CONSOLIDATED STATEMENTS OF CAS7

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	Jun. 30, 2015	Apr. 01, 2015	Jun. 30, 2014
GTN | Transaction between entities under common control | Former parent, TransCanada subsidiaries
GTN ACQUISITION
Business Acquisition, Percentage of Voting Interests Acquired	30.00%	30.00%	30.00%

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS' EQUITY - Business Acquisition, Acquiree [Domain] - 6 months ended Jun. 30, 2015 - USD ($) shares in Millions, $ in Millions	Limited PartnersCommon unitsATM Equity Issuance Program	Limited PartnersCommon units	Limited PartnersClass B unitsUnit issuances	Limited PartnersClass B units	General PartnerATM Equity Issuance Program	General Partner	Accumulated Other Comprehensive Loss		Non-controlling interests	ATM Equity Issuance Program	Unit issuances	Total
Balance as of beginning year at Dec. 31, 2014		$ 1,325				$ 29	$ (2)		$ 234			$ 1,586
Partners' Equity at beginning of year (in units) at Dec. 31, 2014		63.6
Increase (Decrease) in Partners' Equity
Net income		$ 98				3			7			108
Other comprehensive loss							(1)					(1)
Equity issuance, net (Note 7); Unit Issuances (Note 6)	$ 25		$ 95		$ 1					$ 26	$ 95
Equity issuance (Note 7); Unit issuances (Note 6) (in units)	0.4		1.9
Acquisition of the remaining 30 percent interest in GTN (Note 6)		(124)				(3)			(232)			(359)
Equity contribution (Note 6)						2						2
Distributions paid		(107)				(3)			$ (9)			(119)
Balance as of end year at Jun. 30, 2015		$ 1,217		$ 95		$ 29	$ (3)	[1]				$ 1,338
Partners' Equity at End of Year (in units) at Jun. 30, 2015		64		1.9
[1]	Losses related to cash flow hedges reported in Accumulated Other Comprehensive Loss and expected to be reclassified to Net Income in the next 12 months are estimated to be $1 million. These estimates assume constant interest rates over time; however, the amounts reclassified will vary based on actual value of interest rates at the date of settlement.

CONSOLIDATED STATEMENT OF CHAN9

CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS' EQUITY (Parenthetical) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015
Losses related to cash flow hedges reported in Accumulated Other Comprehensive Loss
Losses expected to be reclassified to net income in the next 12 months	$ 1
Former parent, TransCanada subsidiaries | Transaction between entities under common control | GTN
Acquisition of remaining interest
Interest acquired (as a percent)	30.00%

ORGANIZATION

ORGANIZATION	6 Months Ended
	Jun. 30, 2015
ORGANIZATION
ORGANIZATION	NOTE 1 ORGANIZATION TC PipeLines, LP and its subsidiaries are collectively referred to herein as the Partnership. The Partnership was formed by TransCanada PipeLines Limited, a wholly-owned subsidiary of TransCanada Corporation (TransCanada Corporation together with its subsidiaries collectively referred to herein as TransCanada), to acquire, own and participate in the management of energy infrastructure assets in North America.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2015
SIGNIFICANT ACCOUNTING POLICIES
SIGNIFICANT ACCOUNTING POLICIES	NOTE 2 SIGNIFICANT ACCOUNTING POLICIES The accompanying financial statements and related notes have been prepared in accordance with United States generally accepted accounting principles (GAAP) and amounts are stated in U.S. dollars. The results of operations for the three and six months ended June 30, 2015 and 2014 are not necessarily indicative of the results that may be expected for the full fiscal year. The accompanying financial statements should be read in conjunction with the financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2014. That report contains a more comprehensive summary of the Partnership’s significant accounting policies. In the opinion of management, the accompanying financial statements contain all of the appropriate adjustments, all of which are normally recurring adjustments unless otherwise noted, and considered necessary to present fairly the financial position of the Partnership, the results of operations and cash flows for the respective periods. Our significant accounting policies are consistent with those disclosed in Note 2 of the financial statements in our Annual Report on Form 10-K for the year ended December 31, 2014. Certain items from that Note are repeated or updated below as necessary to assist in understanding the accompanying financial statements. (a) Basis of Presentation The Partnership accounts for business acquisitions between itself and TransCanada and its affiliates as transactions between entities under common control. Using this approach, the assets and liabilities of the acquired entities are recorded at TransCanada’s carrying value. In the event recasting is required, the Partnership’s historical financial information will be recast, except net income per common unit, to include the acquired entities for all periods presented. If the fair market value paid for the acquired entities is greater than the recorded net assets of the acquired entities, the excess purchase price paid is recorded as a reduction in Partners’ Equity. Similarly, if the fair market value paid for the acquired entities is less than the recorded net assets of the acquired entities, the excess of assets acquired is recorded as an increase in Partners’ Equity. The Partnership consolidates its investments in GTN, Bison, North Baja and Tuscarora, over which it is able to exercise control. To the extent there are interests owned by other parties, these interests are included in non-controlling interests. The Partnership uses the equity method of accounting for its investments in Northern Border and Great Lakes, over which it is able to exercise significant influence. (b) Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Although management believes these estimates are reasonable, actual results could differ from these estimates.

ACCOUNTING PRONOUNCEMENTS

ACCOUNTING PRONOUNCEMENTS	6 Months Ended
	Jun. 30, 2015
ACCOUNTING PRONOUNCEMENTS
ACCOUNTING PRONOUNCEMENTS	NOTE 3 ACCOUNTING PRONOUNCEMENTS Revenue from contracts with customers In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09 “Revenue from Contracts with Customers (Topic 606).” This guidance supersedes the revenue recognition requirements in Topic 605, Revenue Recognition and most industry-specific guidance. This new guidance requires that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. On July 9, 2015, the FASB voted to defer the effective date by one year to December 15, 2017 for annual reporting periods beginning after that date. The FASB also voted to permit early adoption of the standard, but not before the original effective date of December 15, 2016. This new guidance, once effective, allows two methods in which the amendment can be applied: (1) retrospectively to each prior reporting period presented, or (2) retrospectively with the cumulative effect recognized at the date of initial application. The Partnership is currently evaluating the impact of the adoption of this ASU and has not yet determined the effect on its consolidated financial statements. Consolidation In February 2015, the FASB issued ASU No. 2015-02 “Consolidation (Topic 810),” amendment of previously issued guidance on consolidation. This updated guidance requires that an entity evaluate whether it should consolidate certain legal entities. All legal entities are subject to reevaluation under the revised consolidation model. This guidance is effective from January 1, 2016 and early application is permitted. Application of this amendment could be performed using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the fiscal year of adoption. Alternatively, the amendment could be applied retrospectively. The Partnership is currently evaluating the impact of the adoption of this ASU and has not yet determined the effect on its consolidated financial statements. Imputation of interest In April 2015, the FASB issued ASU No. 2015-03 “Interest – Imputation of Interest (Subtopic 835-30),” an amendment of previously issued guidance on imputation of interest. This updated guidance requires debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of debt liabilities, consistent with debt discount or premiums. The recognition and measurement for debt issuance costs would not be affected. This guidance is effective from January 1, 2016 and early application is permitted. This guidance should be adopted on a retrospective basis, wherein the balance sheet of each individual period presented would be adjusted to reflect the period-specific effects of applying the new guidance. The application of this amendment will result in a reclassification of debt issuance costs currently recorded in Other Assets to an offset of their respective debt liabilities. Earnings Per Share In April 2015, the FASB issued ASU No.2015-06 “Earnings Per Share (Topic 260),” an amendment of previously issued guidance on earnings per share (EPS) as it is being calculated by master limited partnerships. This updated guidance specifies that for purposes of calculating historical EPS under the two-class method, the earnings (losses) of a transferred business before the date of a dropdown transaction should be allocated entirely to the general partner interest, and previously reported EPS of the limited partners would not change as a result of a dropdown transaction. Qualitative disclosures about how the rights to the earnings (losses) differ before and after the dropdown transaction occurs are also required. This guidance is effective from January 1, 2016 and early application is permitted. This guidance should be adopted on a retrospective basis to all financial statements presented. The Partnership is currently evaluating the impact of the adoption of this ASU and has not yet determined the effect on its consolidated financial statements.

INVESTMENTS IN UNCONSOLIDATED A

INVESTMENTS IN UNCONSOLIDATED AFFILIATES	6 Months Ended
	Jun. 30, 2015
INVESTMENTS IN UNCONSOLIDATED AFFILIATES
INVESTMENTS IN UNCONSOLIDATED AFFILIATES	NOTE 4 INVESTMENTS IN UNCONSOLIDATED AFFILIATES Northern Border and Great Lakes are regulated by FERC and are operated by TransCanada. The Partnership uses the equity method of accounting for its interests in its equity investees. Equity Earnings from Investments in Ownership Unconsolidated Affiliates Unconsolidated Affiliates Interest at Three months Six Months (unaudited) June 30, ended June 30, ended June 30, June 30, December 31, (millions of dollars) 2015 2014 2015 2014 2015 2014 Northern Border (a) Great Lakes - (a) Equity earnings from Northern Border is net of the 12-year amortization of a $10 million transaction fee paid to the operator of Northern Border at the time of the Partnership’s additional 20 percent interest acquisition in April 2006. Northern Border The Partnership does not have undistributed earnings from Northern Border for the six months ended June 30, 2015 and 2014. The summarized financial information for Northern Border is as follows: (unaudited) (millions of dollars) June 30, 2015 December 31, 2014 ASSETS Cash and cash equivalents Other current assets Plant, property and equipment, net Other assets LIABILITIES AND PARTNERS’ EQUITY Current liabilities Deferred credits and other Long-term debt, including current maturities Partners’ equity Partners’ capital Accumulated other comprehensive loss ) ) Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars) 2015 Transmission revenues Operating expenses ) ) ) ) Depreciation ) ) ) ) Financial charges and other ) ) ) ) Net income Great Lakes The Partnership made an equity contribution to Great Lakes of $ 4 million in the first quarter of 2015. This amount represents the Partnership’s 46.45 percent share of a $9 million cash call from Great Lakes to make a scheduled debt repayment. The Partnership does not have undistributed earnings from Great Lakes for the six months ended June 30, 2015 and 2014. The summarized financial information for Great Lakes is as follows: (unaudited) (millions of dollars) June 30, 2015 December 31, 2014 ASSETS Current assets Plant, property and equipment, net LIABILITIES AND PARTNERS’ EQUITY Current liabilities Long-term debt, including current maturities Partners’ equity Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars) Transmission revenues Operating expenses ) ) ) ) Depreciation ) ) ) ) Financial charges and other ) ) ) ) Net income

CREDIT FACILITIES, SHORT-TERM L

CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT	6 Months Ended
	Jun. 30, 2015
CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT
CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT	NOTE 5 CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT (unaudited) (millions of dollars) June 30, 2015 December 31, 2014 Senior Credit Facility due 2017 Term Loan Facility due 2018 Short-Term Loan Facility due 2015 4.65% Unsecured Senior Notes due 2021, net of discount (2015 and 2014 – nil) 4.375% Unsecured Senior Notes due 2025, net of $1 million discount - 5.09% Unsecured Senior Notes due 2015 - 5.29% Unsecured Senior Notes due 2020 5.69% Unsecured Senior Notes due 2035 Unsecured Term Loan Facility due 2019 - 3.82% Series D Senior Notes due 2017 Less: current portion The Partnership’s Senior Credit Facility consists of a $500 million senior revolving credit facility with a banking syndicate, maturing November 20, 2017, under which $200 million was outstanding at June 30, 2015 (December 31, 2014 - $330 million), leaving $300 million available for future borrowing. The London Interbank Offered Rate (LIBOR) based interest rate on the Senior Credit Facility averaged 1.44 percent and 1.43 percent for the three and six months ended June 30, 2015, respectively (2014 – 1.41 percent). The LIBOR-based interest rate was 1.44 percent at June 30, 2015 (December 31, 2014 – 1.41 percent). The LIBOR-based interest rate on the Term Loan Facility due 2018 averaged 1.44 percent and 1.43 percent for the three and six months ended June 30, 2015, respectively (2014 – 1.41 percent) . After hedging activity, the interest rate incurred on the Term Loan Facility averaged 1.84 percent for the three and six months ended June 30, 2015 (2014 – 1.83 percent). Prior to hedging activities, the LIBOR-based interest rate was 1.44 percent at June 30, 2015 (December 31, 2014 – 1.41 percent) . The LIBOR-based interest rate on the Short-Term Loan Facility averaged 1.31 percent and 1.30 percent for the three and six months ended June 30, 2015, respectively and was 1.31 percent at June 30, 2015 (December 31, 2014 – 1.28 percent). The Senior Credit Facility, the Term Loan Facility and Short-Term Loan Facility require the Partnership to maintain a certain leverage ratio (debt to adjusted cash flow [net income plus cash distributions received, extraordinary losses, interest expense, expense for taxes paid or accrued, and depreciation and amortization expense less equity earnings and extraordinary gains]). In the quarter in which an acquisition has occurred, and the two quarters following the acquisition, the allowable leverage ratio increases to 5.50 to 1.00. Thereafter, the ratio returns to 5.00 to 1.00. The allowable ratio for the quarter ended June 30, 2015 is 5.50 to 1.00. The leverage ratio was 4.84 to 1.00 as of June 30, 2015. On March 13, 2015, the Partnership closed a $350 million public offering of senior unsecured notes bearing an interest rate of 4.375 percent maturing March 13, 2025. The net proceeds of $346 million were used to fund a portion of the acquisition of the remaining 30 percent interest in GTN (2015 GTN Acquisition – refer to Note 6) and to reduce the amount outstanding under our Senior Credit Facility. The indenture for the notes contains customary investment grade covenants. On June 1, 2015, GTN’s 5.09 percent unsecured Senior Notes matured. Also, on June 1, 2015, GTN entered into a $75 million unsecured variable rate term loan facility (Unsecured Term Loan Facility) which requires yearly principal payments until its maturity on June 1, 2019. The variable interest is based on LIBOR plus an applicable margin. The LIBOR-based interest rate on the Unsecured Term Loan Facility for the month ended June 30, 2015 averaged 1.13 percent and was 1.13 percent at June 30, 2015. GTN’s Senior Notes along with this new Unsecured Term Loan Facility contain a covenant that limits total debt to no greater than 70 percent of GTN’s total capitalization. GTN’s total debt to total capitalization ratio at June 30, 2015 is 43 percent. The Series D Senior Notes, which require yearly principal payments until maturity, are secured by Tuscarora’s transportation contracts, supporting agreements and substantially all of Tuscarora’s property. The note purchase agreements contain certain provisions that include, among other items, limitations on additional indebtedness and distributions to partners. At June 30, 2015, the Partnership was in compliance with its financial covenants, in addition to the other covenants which include restrictions on entering into mergers, consolidations and sales of assets, granting liens, material amendments to the Third Amended and Restated Agreement of Limited Partnership (Partnership Agreement), incurring additional debt and distributions to unitholders. The principal repayments required of the Partnership on its debt are as follows: (unaudited) (millions of dollars) 2015 2016 2017 2018 2019 2020 Thereafter

GTN ACQUISITION

GTN ACQUISITION	6 Months Ended
	Jun. 30, 2015
GTN ACQUISITION
GTN ACQUISITION	NOTE 6 GTN ACQUISITION On April 1, 2015, the Partnership acquired the remaining 30 percent interest of GTN from a subsidiary of TransCanada (2015 GTN Acquisition), which resulted in GTN being wholly-owned by the Partnership. The total purchase price of the 2015 GTN Acquisition was $446 million plus the final purchase price adjustment of $11 million, for a total of $457 million. The purchase price consisted of $264 million in cash (including the final purchase price adjustment of $11 million), the assumption of $98 million in proportional GTN debt and the issuance of $95 million of new Class B units to TransCanada. The Partnership funded the cash portion of the transaction using a portion of the proceeds received on our March 13, 2015 debt offering (see Note 5). The Class B units entitle TransCanada to a distribution based on 30 percent of GTN’s annual distributions as follows: (i) 100 percent of distributions above $20 million through March 31, 2020; and (ii) 25 percent of distributions above $20 million thereafter. Under the terms of the Partnership Agreement, the Class B distribution will be initially calculated to equal 30 percent of GTN’s distributable cash flow for the nine months ending December 31, 2015, less $15 million. Prior to this transaction, the remaining 30 percent interest held by a subsidiary of TransCanada was reflected as a non-controlling interest in the Partnership’s consolidated financial statements. The 2015 GTN Acquisition of this already-consolidated entity was accounted as a transaction between entities under common control, similar to a pooling of interests, whereby the acquired interest was recorded at TransCanada’s carrying value and the total excess purchase price paid was recorded as a reduction in Partners’ Equity. The net purchase price was allocated as follows: (millions of dollars) Net Purchase Price (a) Less: TransCanada’s carrying value of non-controlling interest at April 1, 2015 Excess purchase price (b) (a) Total purchase price of $457 million less the assumption of $98 million of proportional GTN debt by the Partnership. (b) The excess purchase price of $127 million was recorded as a reduction in Partners’ Equity. Our General Partner also contributed approximately $2 million to maintain its effective 2 percent interest in the Partnership.

PARTNERS' EQUITY

PARTNERS' EQUITY	6 Months Ended
	Jun. 30, 2015
PARTNERS' EQUITY
PARTNERS' EQUITY	NOTE 7 PARTNERS’ EQUITY ATM equity issuance program (ATM program) In August 2014, the Partnership entered into an Equity Distribution Agreement (the EDA) with five different financial institutions (Managers), pursuant to which the Partnership may from time to time, offer and sell common units having an aggregate offering price of up to $200 million. Sales of such common units will be made by means of ordinary brokers’ transactions on the New York Stock Exchange (NYSE) at market prices, in block transactions or as otherwise agreed upon by one or more of the Managers and the Partnership. For the six months ended June 30, 2015, the Partnership issued 396,205 common units under the ATM program generating net proceeds of approximately $25 million, plus $1 million from the General Partner to maintain its effective two percent interest. The commissions to our sales agents for the six months ended June 30, 2015 were approximately $256,000. The net proceeds were used for general partnership purposes. Issuance of Class B units On April 1, 2015, we issued 1,900,000 new Class B units to TransCanada with a value of $50 each representing limited partner interests in us, for a total value $95 million. The Class B units contain no mandatory or optional redemption features and are also non-convertible, non-exchangeable, non-voting and rank equally with common units upon liquidation. The Class B units entitle TransCanada to an annual distribution which is an amount based on 30 percent of GTN’s annual distributions as follows: (i) 100 percent of distributions above $20 million through March 31, 2020; and (ii) 25 percent of distributions above $20 million thereafter . Under the terms of the Partnership Agreement, the Class B distribution will initially be calculated to equal 30 percent of GTN’s distributable cash flow for the nine months ending December 31, 2015, less $15 million (refer to Note 6). The Class B distribution is an annual calculation that will be reflected as an increase in the Class B units’ equity account until such amount is declared for distribution and paid in the first quarter beginning 2016 and annually thereafter.

NET INCOME PER COMMON UNIT

NET INCOME PER COMMON UNIT	6 Months Ended
	Jun. 30, 2015
NET INCOME PER COMMON UNIT
NET INCOME PER COMMON UNIT	NOTE 8 NET INCOME PER COMMON UNIT Net income per common unit is computed by dividing net income attributable to controlling interests, after deduction of amounts allocable to the General Partner by the weighted average number of common units outstanding. The amounts allocable to the General Partner equals an amount based upon the General Partner’s effective two percent general partner interest, plus an amount equal to incentive distributions. Incentive distributions are paid to the General Partner if quarterly cash distributions on the common units exceed levels specified in the Partnership Agreement. Incentive distributions allocated to the General Partner for both the three and six months ended June 30, 2015, were $1 million. Incentive distributions allocated to the General Partner for both the three and six months ended June 30, 2014 were $0.3 million. Net income per common unit was determined as follows: Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars, except per common unit amounts) Net income attributable to controlling interests 44 (b) 101 (b) Net income allocated to General Partner Incentive distributions allocated to the General Partner (a) (1) (1) (1) - (2) (1) (2) - Net income allocated to common units 42 (b) 98 (b) Weighted average common units outstanding (millions) – basic and diluted Net income per common unit – basic and diluted $0.66 (b) $ 1.53 (b) $ (a) Under the terms of the Partnership Agreement, for any quarterly period, the participation of the incentive distribution rights (IDRs) is limited to the available cash distributions declared. Accordingly, incentive distributions allocated to the General Partner was based from the Partnership’s available cash during the current reporting period, but declared and paid in the subsequent reporting period. (b) As discussed in Notes 6 and 7, the Class B units entitle TransCanada to a distribution based on achieving the annual threshold. The distribution will be payable in the first quarter with respect to the prior year’s distributions. Consistent with the application of ASC 260 - “Earnings per share,” the Partnership will allocate a portion of net income attributable to controlling interests to the Class B units upon 30 percent of GTN’s total distributable cash flows exceeding $15 million for the nine month period ending December 31, 2015. This allocation will reduce net income allocated to common units and net income per common unit. During the three months ended June 30, 2015, GTN’s total distributable cash flow was $29 million and therefore no portion of net income attributable to controlling interests was allocated to the Class B units.

CASH DISTRIBUTIONS

CASH DISTRIBUTIONS	6 Months Ended
	Jun. 30, 2015
CASH DISTRIBUTIONS
CASH DISTRIBUTIONS	NOTE 9 CASH DISTRIBUTIONS For the three and six months ended June 30, 2015, the Partnership distributed $0.84 and $1.68 per common unit, respectively (2014 – $0.81 and $1.62 per common unit) for a total of $55 million and $110 million, respectively (2014 - $52 million and $103 million). The distributions paid for the three and six months ended June 30, 2015 included an incentive distribution to the General Partner of approximately $0.3 million and $0.6 million, respectively. There were no incentive distributions paid to the General Partner for the three and six months ended June 30, 2014.

CHANGE IN OPERATING WORKING CAP

CHANGE IN OPERATING WORKING CAPITAL	6 Months Ended
	Jun. 30, 2015
CHANGE IN OPERATING WORKING CAPITAL
CHANGE IN OPERATING WORKING CAPITAL	NOTE 10 CHANGE IN OPERATING WORKING CAPITAL (unaudited) Six months ended June 30, (millions of dollars) Change in accounts receivable and other (a) Change in accounts payable and accrued liabilities (a) Change in accounts payable to affiliates Change in accrued interest - Change in operating working capital (a) Excludes certain non-cash items primarily related to accruals of $9 million for construction of GTN’s Carty Lateral and compressor overhauls.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	6 Months Ended
	Jun. 30, 2015
RELATED PARTY TRANSACTIONS
RELATED PARTY TRANSACTIONS	NOTE 11 RELATED PARTY TRANSACTIONS The Partnership does not have any employees. The management and operating functions are provided by the General Partner. The General Partner does not receive a management fee in connection with its management of the Partnership. The Partnership reimburses the General Partner for all costs of services provided, including the costs of employee, officer and director compensation and benefits, and all other expenses necessary or appropriate to the conduct of the business of, and allocable to, the Partnership. Such costs include (i) overhead costs (such as office space and equipment) and (ii) out-of-pocket expenses related to the provision of such services. The Partnership Agreement provides that the General Partner will determine the costs that are allocable to the Partnership in any reasonable manner determined by the General Partner in its sole discretion. Total costs charged to the Partnership by the General Partner were $1 million for both the three and six months ended June 30, 2015 (2014 – $1 million and $2 million). As operator, TransCanada’s subsidiaries provide capital and operating services to our pipeline systems. TransCanada’s subsidiaries incur costs on behalf of our pipeline systems, including, but not limited to, employee salary and benefit costs, and property and liability insurance costs. Capital and operating costs charged to our pipeline systems for the three and six months ended June 30, 2015 and 2014 by TransCanada’s subsidiaries and amounts payable to TransCanada’s subsidiaries at June 30, 2015 and December 31, 2014 are summarized in the following tables: Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars) 2015 2014 Capital and operating costs charged by TransCanada’s subsidiaries to: Great Lakes (a) Northern Border (a) GTN (a) Bison (a) North Baja Tuscarora Impact on the Partnership’s net income: Great Lakes Northern Border GTN (b) Bison (c) North Baja Tuscarora (a) Represents 100 percent of the costs. (b) In April 2015, the Partnership acquired the remaining 30 percent interest in GTN. See discussion in Note 6. (c) In October 2014, the Partnership acquired the remaining 30 percent interest in Bison. (unaudited) (millions of dollars) June 30, 2015 December 31, 2014 Amount payable to TransCanada’s subsidiaries for costs charged in the period by: GTN Northern Border (a) Bison Great Lakes (a) North Baja Tuscarora (a) Represents 100 percent of the costs. Great Lakes’ earns revenues from TransCanada and its affiliates under transportation contracts on multiple paths at various rates. Great Lakes earned $18 million and $47 million of transportation revenues under these contracts for the three and six months ended June 30, 2015, respectively (2014 - $13 million and $35 million). These amounts represent 63 percent and 62 percent of total revenues earned by Great Lakes for the three and six months ended June 30, 2015, respectively (2014 – 43 percent and 46 percent). Great Lakes also earned $1 million of affiliated rental revenue for the three and six months ended June 30, 2015 (2014 – $1 million). Revenue from TransCanada and its affiliates of $8 million and $22 million are included in the Partnership’s equity earnings from Great Lakes for the three and six months ended June 30, 2015, respectively (2014 - $6 million and $17 million). At June 30, 2015, $30 million was included in Great Lakes’ receivables in regards to the transportation contracts with TransCanada and its affiliates (December 31, 2014 - $15 million). Effective November 1, 2014, Great Lakes executed contracts with its affiliate, ANR Pipeline Company (ANR) to provide firm service in Michigan and Wisconsin. These contracts were at the maximum FERC authorized rate and were intended to replace historical contracts. On December 3, 2014, the FERC accepted and suspended Great Lakes’ tariff records to become effective May 3, 2015, subject to refund. On February 2, 2015, FERC issued an Order granting a rehearing and clarification request submitted by Great Lakes, which allowed additional time for FERC to consider Great Lakes’ request. Following extensive discussions with numerous shippers and other stakeholders, on April 20, 2015, ANR filed a settlement with FERC that included an agreement by ANR to pay Great Lakes the difference between the historical and maximum rates, subject to approval by FERC. Absent clarification or approval of the settlement by FERC, Great Lakes provided service to ANR under multiple service agreements and rates through May 3, 2015 when Great Lakes’ tariff records became effective and subject to refund. Great Lakes deferred an approximate $9.4 million of revenue related to services performed in 2014 and approximately $14 million of additional revenue related to services performed through May 3, 2015 under such agreements that may not ultimately be collected if the settlement is not approved by FERC. In April 2014, the Partnership paid $25 million to a subsidiary of TransCanada as additional consideration on the 2013 Acquisition. The additional consideration paid was due to the transportation service agreement executed by Portland General Electric Company with GTN relating to the Carty Lateral project.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2015
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS	NOTE 12 FAIR VALUE MEASUREMENTS (a) Fair Value Hierarchy Under ASC 820, Fair Value Measurements and Disclosures, fair value measurements are characterized in one of three levels based upon the inputs used to arrive at the measurement. The three levels of the fair value hierarchy are as follows: · Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the measurement date. · Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. · Level 3 inputs are unobservable inputs for the asset or liability. When appropriate, valuations are adjusted for various factors including credit considerations. Such adjustments are generally based on available market evidence. In the absence of such evidence, management’s best estimate is used. (b) Fair Value of Financial Instruments The carrying value of cash and cash equivalents, accounts receivable and other, accounts payable and accrued liabilities, accounts payable to affiliates and accrued interest approximate their fair values because of the short maturity or duration of these instruments, or because the instruments bear a variable rate of interest or a rate that approximates current rates. The fair value of the Partnership’s long-term debt is estimated by discounting the future cash flows of each instrument at estimated current borrowing rates. The fair value of interest rate derivatives is calculated using the income approach, which uses period-end market rates and applies a discounted cash flow valuation model. The estimated fair value of the Partnership’s debt as at June 30, 2015 and December 31, 2014 are as follows: (unaudited) June 30, 2015 December 31, 2014 (millions of dollars) Carrying Value Fair Value Carrying Value Fair Value Senior Credit Facility due 2017 Term Loan Facility due 2018 Short-Term Loan Facility due 2015 4.65% Senior Notes due 2021, net 4.375% Senior Notes due 2025, net - - 5.09% Unsecured Senior Notes due 2015 - - Unsecured Term Loan facility due 2019 - - 5.29% Unsecured Senior Notes due 2020 5.69% Unsecured Senior Notes due 2035 3.82% Series D Senior Notes due 2017 Long-term debt is recorded at amortized cost and classified in Level II of the fair value hierarchy for fair value disclosure purposes. Interest rate derivative assets and liabilities are classified in Level II for all periods presented where the fair value is determined by using valuation techniques that refer to observable market data or estimated market prices. Market risk is the risk that changes in market interest rates may result in fluctuations in the fair values or cash flows of financial instruments. The Partnership’s floating rate debt is subject to LIBOR benchmark interest rate risk. The Partnership uses interest rate derivatives to manage its exposure to interest rate risk. We regularly assess the impact of interest rate fluctuations on future cash flows and evaluate hedging opportunities to mitigate our interest rate risk. The interest rate swaps are structured such that the cash flows of the derivative instruments match those of the variable rate of interest on the Term Loan Facility. The Partnership hedged interest payments on $150 million of variable-rate Term Loan Facility with interest rate swaps effective September 3, 2013 and maturing July 1, 2018, at a weighted average fixed interest rate of 2.79 percent. At June 30, 2015, the fair value of the interest rate swaps accounted for as cash flow hedges was a liability of $2 million (both on a gross and net basis) (December 31, 2014 - $1 million). The Partnership did not record any amounts in net income related to ineffectiveness for interest rate hedges for the three and six months ended June 30, 2015 (2014 – nil). The change in fair value of interest rate derivative instruments recognized in other comprehensive income was nil and a loss of $1 million for the three and six months ended June 30, 2015, respectively (2014 – $1 million). For the three and six months ended June 30, 2015, the net realized loss related to the interest rate swaps was nil and $1 million, respectively, and was included in financial charges and other (2014 – $1 million). The Partnership has no master netting agreements; however, contracts contain provisions with rights of offset. The Partnership has elected to present the fair value of derivative instruments with the right to offset on a gross basis in the balance sheet. Had the Partnership elected to present these instruments on a net basis, there would be no effect on the consolidated balance sheet as of June 30, 2015 and December 31, 2014.

ACCOUNTS RECEIVABLE AND OTHER

ACCOUNTS RECEIVABLE AND OTHER	6 Months Ended
	Jun. 30, 2015
ACCOUNTS RECEIVABLE AND OTHER
ACCOUNTS RECEIVABLE AND OTHER	NOTE 13 ACCOUNTS RECEIVABLE AND OTHER (unaudited) (millions of dollars) June 30, 2015 December 31, 2014 Trade accounts receivable, net of allowance of nil Accounts receivable from affiliates Other

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	6 Months Ended
	Jun. 30, 2015
SUBSEQUENT EVENTS
SUBSEQUENT EVENTS	NOTE 14 SUBSEQUENT EVENTS Management of the Partnership has reviewed subsequent events through August 7, 2015, the date the financial statements were issued, and concluded there were no events or transactions during this period that would require recognition or disclosure in the consolidated financial statements other than what is disclosed here and/or those already disclosed in the preceding notes. On July 23, 2015, the board of directors of our General Partner declared the Partnership’s second quarter 2015 cash distribution in the amount of $0.89 per common unit payable on August 14, 2015 to unitholders of record as of August 4, 2015. Northern Border declared its second quarter 2015 distribution of $42 million on July 22, 2015, of which the Partnership will receive its 50 percent share or $21 million on August 3, 2015. Great Lakes declared its second quarter 2015 distribution of $7 million on July 22, 2015, of which the Partnership will receive its 46.45 percent share or $3 million on August 3, 2015.

SIGNIFICANT ACCOUNTING POLICI24

SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2015
SIGNIFICANT ACCOUNTING POLICIES
Basis of Presentation	(a) Basis of Presentation The Partnership accounts for business acquisitions between itself and TransCanada and its affiliates as transactions between entities under common control. Using this approach, the assets and liabilities of the acquired entities are recorded at TransCanada’s carrying value. In the event recasting is required, the Partnership’s historical financial information will be recast, except net income per common unit, to include the acquired entities for all periods presented. If the fair market value paid for the acquired entities is greater than the recorded net assets of the acquired entities, the excess purchase price paid is recorded as a reduction in Partners’ Equity. Similarly, if the fair market value paid for the acquired entities is less than the recorded net assets of the acquired entities, the excess of assets acquired is recorded as an increase in Partners’ Equity. The Partnership consolidates its investments in GTN, Bison, North Baja and Tuscarora, over which it is able to exercise control. To the extent there are interests owned by other parties, these interests are included in non-controlling interests. The Partnership uses the equity method of accounting for its investments in Northern Border and Great Lakes, over which it is able to exercise significant influence.
Use of Estimates	(b) Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Although management believes these estimates are reasonable, actual results could differ from these estimates.

INVESTMENTS IN UNCONSOLIDATED25

INVESTMENTS IN UNCONSOLIDATED AFFILIATES (Tables)	6 Months Ended
	Jun. 30, 2015
INVESTMENTS IN UNCONSOLIDATED AFFILIATES
Schedule of interests in equity investees	Equity Earnings from Investments in Ownership Unconsolidated Affiliates Unconsolidated Affiliates Interest at Three months Six Months (unaudited) June 30, ended June 30, ended June 30, June 30, December 31, (millions of dollars) 2015 2014 2015 2014 2015 2014 Northern Border (a) Great Lakes - (a) Equity earnings from Northern Border is net of the 12-year amortization of a $10 million transaction fee paid to the operator of Northern Border at the time of the Partnership’s additional 20 percent interest acquisition in April 2006.
Northern Border
Investments in unconsolidated affiliates
Summarized financial information for equity investees	(unaudited) (millions of dollars) June 30, 2015 December 31, 2014 ASSETS Cash and cash equivalents Other current assets Plant, property and equipment, net Other assets LIABILITIES AND PARTNERS’ EQUITY Current liabilities Deferred credits and other Long-term debt, including current maturities Partners’ equity Partners’ capital Accumulated other comprehensive loss ) ) Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars) 2015 Transmission revenues Operating expenses ) ) ) ) Depreciation ) ) ) ) Financial charges and other ) ) ) ) Net income
Great Lakes
Investments in unconsolidated affiliates
Summarized financial information for equity investees	(unaudited) (millions of dollars) June 30, 2015 December 31, 2014 ASSETS Current assets Plant, property and equipment, net LIABILITIES AND PARTNERS’ EQUITY Current liabilities Long-term debt, including current maturities Partners’ equity Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars) Transmission revenues Operating expenses ) ) ) ) Depreciation ) ) ) ) Financial charges and other ) ) ) ) Net income

CREDIT FACILITIES, SHORT-TERM26

CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT (Tables)	6 Months Ended
	Jun. 30, 2015
CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT
Schedule of credit facilities, short-term loan facility and long-term debt	(unaudited) (millions of dollars) June 30, 2015 December 31, 2014 Senior Credit Facility due 2017 Term Loan Facility due 2018 Short-Term Loan Facility due 2015 4.65% Unsecured Senior Notes due 2021, net of discount (2015 and 2014 – nil) 4.375% Unsecured Senior Notes due 2025, net of $1 million discount - 5.09% Unsecured Senior Notes due 2015 - 5.29% Unsecured Senior Notes due 2020 5.69% Unsecured Senior Notes due 2035 Unsecured Term Loan Facility due 2019 - 3.82% Series D Senior Notes due 2017 Less: current portion
Schedule of principal repayments required on debt	(unaudited) (millions of dollars) 2015 2016 2017 2018 2019 2020 Thereafter

GTN ACQUISITION (Tables)

GTN ACQUISITION (Tables)	6 Months Ended
	Jun. 30, 2015
GTN
GTN ACQUISITION
Schedule of purchase price	(millions of dollars) Net Purchase Price (a) Less: TransCanada’s carrying value of non-controlling interest at April 1, 2015 Excess purchase price (b) (a) Total purchase price of $457 million less the assumption of $98 million of proportional GTN debt by the Partnership. (b) The excess purchase price of $127 million was recorded as a reduction in Partners’ Equity.

NET INCOME PER COMMON UNIT (Tab

NET INCOME PER COMMON UNIT (Tables)	6 Months Ended
	Jun. 30, 2015
NET INCOME PER COMMON UNIT
Schedule of net income per common unit	Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars, except per common unit amounts) Net income attributable to controlling interests 44 (b) 101 (b) Net income allocated to General Partner Incentive distributions allocated to the General Partner (a) (1) (1) (1) - (2) (1) (2) - Net income allocated to common units 42 (b) 98 (b) Weighted average common units outstanding (millions) – basic and diluted Net income per common unit – basic and diluted $0.66 (b) $ 1.53 (b) $ (a) Under the terms of the Partnership Agreement, for any quarterly period, the participation of the incentive distribution rights (IDRs) is limited to the available cash distributions declared. Accordingly, incentive distributions allocated to the General Partner was based from the Partnership’s available cash during the current reporting period, but declared and paid in the subsequent reporting period. (b) As discussed in Notes 6 and 7, the Class B units entitle TransCanada to a distribution based on achieving the annual threshold. The distribution will be payable in the first quarter with respect to the prior year’s distributions. Consistent with the application of ASC 260 - “Earnings per share,” the Partnership will allocate a portion of net income attributable to controlling interests to the Class B units upon 30 percent of GTN’s total distributable cash flows exceeding $15 million for the nine month period ending December 31, 2015. This allocation will reduce net income allocated to common units and net income per common unit.

CHANGE IN OPERATING WORKING C29

CHANGE IN OPERATING WORKING CAPITAL (Tables)	6 Months Ended
	Jun. 30, 2015
CHANGE IN OPERATING WORKING CAPITAL
Summary of change in operating working capital	(unaudited) Six months ended June 30, (millions of dollars) Change in accounts receivable and other (a) Change in accounts payable and accrued liabilities (a) Change in accounts payable to affiliates Change in accrued interest - Change in operating working capital (a) Excludes certain non-cash items primarily related to accruals of $9 million for construction of GTN’s Carty Lateral and compressor overhauls.

RELATED PARTY TRANSACTIONS (Tab

RELATED PARTY TRANSACTIONS (Tables)	6 Months Ended
	Jun. 30, 2015
RELATED PARTY TRANSACTIONS
Summary of capital and operating costs charged to pipeline systems by related party	Three months ended Six months ended (unaudited) June 30, June 30, (millions of dollars) 2015 2014 Capital and operating costs charged by TransCanada’s subsidiaries to: Great Lakes (a) Northern Border (a) GTN (a) Bison (a) North Baja Tuscarora Impact on the Partnership’s net income: Great Lakes Northern Border GTN (b) Bison (c) North Baja Tuscarora (a) Represents 100 percent of the costs. (b) In April 2015, the Partnership acquired the remaining 30 percent interest in GTN. See discussion in Note 6. (c) In October 2014, the Partnership acquired the remaining 30 percent interest in Bison.
Summary of amount payable to related party for costs charged	(unaudited) (millions of dollars) June 30, 2015 December 31, 2014 Amount payable to TransCanada’s subsidiaries for costs charged in the period by: GTN Northern Border (a) Bison Great Lakes (a) North Baja Tuscarora (a) Represents 100 percent of the costs.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2015
FAIR VALUE MEASUREMENTS
Schedule of estimated fair value of debt	(unaudited) June 30, 2015 December 31, 2014 (millions of dollars) Carrying Value Fair Value Carrying Value Fair Value Senior Credit Facility due 2017 Term Loan Facility due 2018 Short-Term Loan Facility due 2015 4.65% Senior Notes due 2021, net 4.375% Senior Notes due 2025, net - - 5.09% Unsecured Senior Notes due 2015 - - Unsecured Term Loan facility due 2019 - - 5.29% Unsecured Senior Notes due 2020 5.69% Unsecured Senior Notes due 2035 3.82% Series D Senior Notes due 2017

ACCOUNTS RECEIVABLE AND OTHER (

ACCOUNTS RECEIVABLE AND OTHER (Tables)	6 Months Ended
	Jun. 30, 2015
ACCOUNTS RECEIVABLE AND OTHER
Schedule of accounts receivable and other	(unaudited) (millions of dollars) June 30, 2015 December 31, 2014 Trade accounts receivable, net of allowance of nil Accounts receivable from affiliates Other

INVESTMENTS IN UNCONSOLIDATED33

INVESTMENTS IN UNCONSOLIDATED AFFILIATES (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			6 Months Ended
	Apr. 30, 2006	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Investments in unconsolidated affiliates
Equity Earnings from Unconsolidated Affiliates		$ 15		$ 18	$ 46	$ 51
Investments in Unconsolidated Affiliates		$ 1,158			1,158		$ 1,177
Equity contribution					$ 4	4
Northern Border
Investments in unconsolidated affiliates
Transaction fee	$ 10
Interest acquired by Partnership (as a percent)	20.00%
Great Lakes
Investments in unconsolidated affiliates
Total cash call issued to fund debt repayment			$ 9
Northern Border
Investments in unconsolidated affiliates
Ownership interest (as a percent)		50.00%			50.00%
Equity Earnings from Unconsolidated Affiliates		$ 15		16	$ 34	39
Investments in Unconsolidated Affiliates		492			492		505
Amortization period of transaction fee	12 years
Assets
Cash and cash equivalents		40			40		41
Other current assets		32			32		34
Plant, property and equipment, net		1,142			1,142		1,163
Other assets		34			34		34
Assets, total		1,248			1,248		1,272
LIABILITIES AND PARTNERS' EQUITY
Current liabilities		63			63		64
Deferred credits and other		24			24		22
Long-term debt, including current maturities		411			411		411
Partners' equity
Partners' equity		752			752		777
Accumulated other comprehensive loss		(2)			(2)		(2)
Liabilities and Partners' Equity, total		1,248			1,248		1,272
Revenues (expenses)
Transmission revenues		69		69	144	155
Operating expenses		(18)		(16)	(34)	(34)
Depreciation		(14)		(15)	(29)	(30)
Financial charges and other		(6)		(6)	(11)	(12)
Net income		$ 31		32	$ 70	79
Great Lakes
Investments in unconsolidated affiliates
Ownership interest (as a percent)		46.45%	46.45%		46.45%
Equity Earnings from Unconsolidated Affiliates				2	$ 12	12
Investments in Unconsolidated Affiliates		$ 666			666		672
Equity contribution			$ 4
Assets
Current assets		70			70		66
Plant, property and equipment, net		736			736		748
Assets, total		806			806		814
LIABILITIES AND PARTNERS' EQUITY
Current liabilities		52			52		38
Long-term debt, including current maturities		307			307		316
Partners' equity
Partners' equity		447			447		460
Liabilities and Partners' Equity, total		806			806		$ 814
Revenues (expenses)
Transmission revenues		28		29	76	77
Operating expenses		(14)		(12)	(25)	(24)
Depreciation		(7)		(7)	(14)	(14)
Financial charges and other		(6)		(6)	(12)	(13)
Net income		$ 1		$ 4	$ 25	$ 26

CREDIT FACILITIES, SHORT-TERM34

CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT (Details) - USD ($)	Jun. 30, 2015	Mar. 13, 2015	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 01, 2015	May. 31, 2015	Apr. 01, 2015	Dec. 31, 2014
Credit facilities, short-term loan facility and long-term debt
Total credit facilities and long-term debt	$ 1,914,000,000		$ 1,914,000,000	$ 1,914,000,000		$ 1,914,000,000					$ 1,695,000,000
Less: current portion	184,000,000		184,000,000	184,000,000		184,000,000					249,000,000
Long-term debt	$ 1,730,000,000		$ 1,730,000,000	$ 1,730,000,000		1,730,000,000					1,446,000,000
Net proceeds						$ 424,000,000	$ 15,000,000
GTN | Former parent, TransCanada subsidiaries | Transaction between entities under common control
Credit facilities, short-term loan facility and long-term debt
Interest acquired by Partnership (as a percent)	30.00%		30.00%	30.00%	30.00%	30.00%	30.00%			30.00%
Senior Credit Facility, Term Loan Facility and Short-Term Loan Facility
Credit facilities, short-term loan facility and long-term debt
Leverage ratio (as a percent)	4.84%
Senior Credit Facility, Term Loan Facility and Short-Term Loan Facility | Debt agreement covenants, initial period after occurrence of acquisition
Credit facilities, short-term loan facility and long-term debt
Additional period immediately following the fiscal quarter in which a specified material acquisition occurs						6 months
Senior Credit Facility, Term Loan Facility and Short-Term Loan Facility | Debt agreement covenants, initial period after occurrence of acquisition | Maximum
Credit facilities, short-term loan facility and long-term debt
Leverage ratio (as a percent)						5.50%
Senior Credit Facility, Term Loan Facility and Short-Term Loan Facility | Debt agreement covenants, periods subsequent to initial period after occurrence of acquisition | Maximum
Credit facilities, short-term loan facility and long-term debt
Leverage ratio (as a percent)						5.00%
Term loan | Short-Term Loan Facility due 2015
Credit facilities, short-term loan facility and long-term debt
Total credit facilities and long-term debt	$ 170,000,000		$ 170,000,000	$ 170,000,000		$ 170,000,000					$ 170,000,000
Term loan | Short-Term Loan Facility due 2015 | LIBOR
Credit facilities, short-term loan facility and long-term debt
Variable rate basis						LIBOR
Debt average interest rate (as a percent)				1.31%		1.30%
Debt interest rate, at period end (as a percent)	1.31%		1.31%	1.31%		1.31%					1.28%
Senior revolving credit facility | Senior Credit Facility due 2017
Credit facilities, short-term loan facility and long-term debt
Total credit facilities and long-term debt	$ 200,000,000		$ 200,000,000	$ 200,000,000		$ 200,000,000					$ 330,000,000
Maximum borrowing capacity	500,000,000		500,000,000	500,000,000		500,000,000
Amount outstanding under credit facility	200,000,000		200,000,000	200,000,000		200,000,000					$ 330,000,000
Remaining borrowing capacity	$ 300,000,000		$ 300,000,000	$ 300,000,000		$ 300,000,000
Senior revolving credit facility | Senior Credit Facility due 2017 | LIBOR
Credit facilities, short-term loan facility and long-term debt
Variable rate basis				LIBOR		LIBOR
Debt average interest rate (as a percent)				1.44%	1.41%	1.43%	1.41%
Debt interest rate, at period end (as a percent)	1.44%		1.44%	1.44%		1.44%					1.41%
Term loan | Term Loan Facility due 2018
Credit facilities, short-term loan facility and long-term debt
Total credit facilities and long-term debt	$ 500,000,000		$ 500,000,000	$ 500,000,000		$ 500,000,000					$ 500,000,000
Term loan | Term Loan Facility due 2018 | LIBOR borrowings | LIBOR
Credit facilities, short-term loan facility and long-term debt
Variable rate basis				LIBOR		LIBOR
Debt average interest rate (as a percent)				1.44%		1.43%	1.41%
Debt interest rate, at period end (as a percent)	1.44%		1.44%	1.44%		1.44%					1.41%
Term loan | Term Loan Facility due 2018 | LIBOR borrowings | LIBOR | Hedges of cash flows | Interest rate swaps
Credit facilities, short-term loan facility and long-term debt
Debt average interest rate (as a percent)				1.84%	1.83%	1.84%	1.83%
Unsecured debt | 4.65% Senior Notes due 2021
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	4.65%		4.65%	4.65%		4.65%					4.65%
Discount	$ 0		$ 0	$ 0		$ 0					$ 0
Total credit facilities and long-term debt	$ 350,000,000		$ 350,000,000	$ 350,000,000		$ 350,000,000					$ 350,000,000
Unsecured debt | 4.375% Senior Notes due 2025
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	4.375%	4.375%	4.375%	4.375%		4.375%
Discount	$ 1,000,000		$ 1,000,000	$ 1,000,000		$ 1,000,000
Total credit facilities and long-term debt	$ 349,000,000		$ 349,000,000	$ 349,000,000		$ 349,000,000
Amount of debt		$ 350,000,000
Net proceeds		$ 346,000,000
Unsecured debt | 5.09% Senior Notes due 2015
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)											5.09%
Total credit facilities and long-term debt											$ 75,000,000
Unsecured debt | 5.29% Senior Notes due 2020
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	5.29%		5.29%	5.29%		5.29%					5.29%
Total credit facilities and long-term debt	$ 100,000,000		$ 100,000,000	$ 100,000,000		$ 100,000,000					$ 100,000,000
Unsecured debt | 5.69% Senior Notes due 2035
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	5.69%		5.69%	5.69%		5.69%					5.69%
Total credit facilities and long-term debt	$ 150,000,000		$ 150,000,000	$ 150,000,000		$ 150,000,000					$ 150,000,000
Unsecured debt | Term Loan Facility due 2019
Credit facilities, short-term loan facility and long-term debt
Total credit facilities and long-term debt	$ 75,000,000		$ 75,000,000	$ 75,000,000		$ 75,000,000
Secured debt | 3.82% Series D Senior Notes due 2017
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	3.82%		3.82%	3.82%		3.82%					3.82%
Total credit facilities and long-term debt	$ 20,000,000		$ 20,000,000	$ 20,000,000		$ 20,000,000					$ 20,000,000
GTN
Credit facilities, short-term loan facility and long-term debt
Percentage of debt to total capitalization, actual	43.00%		43.00%	43.00%		43.00%
GTN | Unsecured debt | 5.09% Senior Notes due 2015
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)									5.09%
GTN | Unsecured debt | Term Loan Facility due 2019 | Maximum
Credit facilities, short-term loan facility and long-term debt
Percentage of debt to total capitalization, covenant			70.00%
GTN | Unsecured debt | Term Loan Facility due 2019 | LIBOR
Credit facilities, short-term loan facility and long-term debt
Debt average interest rate (as a percent)			1.13%
Debt interest rate, at period end (as a percent)	1.13%		1.13%	1.13%		1.13%
Amount of debt								$ 75,000,000
GTN | Senior Notes | Maximum
Credit facilities, short-term loan facility and long-term debt
Percentage of debt to total capitalization, covenant						70.00%

CREDIT FACILITIES, SHORT-TERM35

CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT (Details 2) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Principal repayments required on debt
2,015	$ 174
2,016	14
2,017	222
2,018	520
2,019	35
2,020	100
Thereafter	849
Total credit facilities and long-term debt	$ 1,914	$ 1,695

GTN ACQUISITION (Details)

GTN ACQUISITION (Details) - USD ($)	Apr. 01, 2015	Jun. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014
Acquisition
Total cash consideration			$ 264,000,000
GTN | Former parent, TransCanada subsidiaries | Transaction between entities under common control
Acquisition
Interest acquired (as a percent)	30.00%	30.00%	30.00%		30.00%
Purchase price adjustments	$ 11,000,000
Purchase price	457,000,000
Total cash consideration	264,000,000
Assumption of proportional debt	98,000,000
GTN | Former parent, TransCanada subsidiaries | Transaction between entities under common control | Previously reported
Acquisition
Purchase price	446,000,000
Partnership interest | Class B units | GTN | Former parent, TransCanada subsidiaries | Transaction between entities under common control
Acquisition
Equity issuance	$ 95,000,000
GTN | Class B units | TransCanada | Distributions
Distributions
Portion of GTN's annual distributions to which the Class B units are entitled to receive a percentage share of the distributions above threshold (as a percent)		30.00%
Percentage applied to 30 percent of GTN's distributions above threshold through March 31, 2020		100.00%
Threshold of 30 percent of GTN's annual distributions for payment to Class B units at specified percentage		$ 20,000,000
Percentage applied to 30 percent of GTN's distributions above threshold after March 31, 2020		25.00%
Effective percentage applied to GTN's distributions above threshold (as a percent)		30.00%
Prorated threshold of GTN's distributions for payment to Class B units		$ 15,000,000
TransCanada | GTN
Noncontrolling interest
Remaining noncontrolling ownership interest (as a percent)				30.00%

GTN ACQUISITION (Details 2)

GTN ACQUISITION (Details 2) - USD ($) $ in Millions	Apr. 01, 2015	Jun. 30, 2015
Net purchase price allocation
Reduction in Partners' Equity		$ 359
GTN | Former parent, TransCanada subsidiaries | Transaction between entities under common control
Net purchase price allocation
Net Purchase Price	$ 359
Less: TransCanada's carrying value of non-controlling interest as April 1, 2015	232
Excess purchase price	127
Purchase price	457
Assumption of proportional debt	98
GTN | Former parent, TransCanada subsidiaries | Transaction between entities under common control | Limited Partner and General Partner interests combined
Net purchase price allocation
Reduction in Partners' Equity	$ 127

GTN ACQUISITION (Details 3)

GTN ACQUISITION (Details 3) - USD ($) $ in Millions	Apr. 02, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
GTN ACQUISITION
Equity contribution				$ 2
General Partner
GTN ACQUISITION
Equity contribution				$ 2
General Partner | Partnership
GTN ACQUISITION
Equity contribution	$ 2
General Partner | TC PipeLines GP, Inc.
GTN ACQUISITION
Ownership interest in the Partnership (as a percent)	2.00%	2.00%	2.00%	2.00%	2.00%

PARTNERS' EQUITY (Details)

PARTNERS' EQUITY (Details)	Apr. 02, 2015	Aug. 31, 2014USD ($)Institution	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015USD ($)shares	Jun. 30, 2014
Partners' Equity
Equity contribution					$ 2,000,000
General Partner
Partners' Equity
Equity contribution					$ 2,000,000
TC PipeLines GP, Inc. | General Partner
Partners' Equity
Ownership interest in the Partnership (as a percent)	2.00%		2.00%	2.00%	2.00%	2.00%
ATM Equity Issuance Program | Common units
Partners' Equity
Number of financial institutions | Institution		5
Units sold | shares					396,205
Net proceeds from public offering of common units					$ 25,000,000
Sales agent commissions					256,000
ATM Equity Issuance Program | TC PipeLines GP, Inc. | General Partner
Partners' Equity
Equity contribution					$ 1,000,000
ATM Equity Issuance Program | Maximum | Common units
Partners' Equity
Aggregate offering price of units		$ 200,000,000
ATM Equity Issuance Program | Minimum | Common units
Partners' Equity
Number of managers to agree with equity sale method | Institution		1

PARTNERS' EQUITY (Details 2)

PARTNERS' EQUITY (Details 2) - Class B units - USD ($)	Apr. 01, 2015	Jun. 30, 2015
Former parent, TransCanada subsidiaries | Transaction between entities under common control | Partnership interest | GTN
Partners' Equity
Units issued (in units)	1,900,000
Value per unit (in dollars per unit)	$ 50
Value of units issued	$ 95,000,000
GTN | TransCanada | Distributions
Partners' Equity
Portion of GTN's annual distributions to which the Class B units are entitled to receive a percentage share of the distributions above threshold (as a percent)		30.00%
Percentage applied to 30 percent of GTN's distributions above threshold through March 31, 2020		100.00%
Threshold of GTN's annual distributions for payment to Class B units		$ 20,000,000
Percentage applied to GTN's distributions above threshold after March 31, 2020		25.00%
Initial effective percentage applied to GTN's distributions above threshold		30.00%
Prorated threshold of GTN's distributions for payment to Class B units		$ 15,000,000

NET INCOME PER COMMON UNIT (Det

NET INCOME PER COMMON UNIT (Details) - USD ($) $ in Millions	Apr. 02, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Partners' Equity
Incentive Distributions		$ 1		$ 1
TC PipeLines GP, Inc. | General Partner
Partners' Equity
General partner interest (as a percent)	2.00%	2.00%	2.00%	2.00%	2.00%
Incentive Distributions		$ 1	$ 0.3	$ 1	$ 0.3

NET INCOME PER COMMON UNIT (D42

NET INCOME PER COMMON UNIT (Details 2) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net income per common unit
Net income attributable to controlling interests	$ 44	$ 37	$ 101	$ 94
Less: Net income allocated to the General Partner, including incentive distributions	(1)	(1)	(2)	(2)
Incentive distributions allocated to the General Partner	(1)		(1)
Common units
Net income per common unit
Net income allocated to limited partners	$ 42	$ 36	$ 98	$ 92
Weighted average common units outstanding (millions) - basic (in units)	63.8	62.3	63.7	62.3
Weighted average common units outstanding (millions) - diluted (in units)	63.8	62.3	63.7	62.3
Net income per common unit - basic (in dollars per unit)	$ 0.66	$ 0.58	$ 1.53	$ 1.48
Net income per common unit - diluted (in dollars per unit)	$ 0.66	$ 0.58	$ 1.53	$ 1.48

NET INCOME PER COMMON UNIT (D43

NET INCOME PER COMMON UNIT (Details 3) - 3 months ended Jun. 30, 2015 - GTN - USD ($)	Total
Partners' Equity
Total distributable cash flows	$ 29,000,000
Class B units | TransCanada | Distributions
Partners' Equity
Initial effective percentage applied to GTN's distributions above threshold	30.00%
Prorated threshold of GTN's distributions for payment to Class B units	$ 15,000,000

CASH DISTRIBUTIONS (Details)

CASH DISTRIBUTIONS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
General Partner
Distributions
Incentive distributions allocated to the General Partner	$ 0.3	$ 0	$ 0.6	$ 0
Common units
Distributions
Partnership distribution (in dollars per unit)	$ 0.84	$ 0.81	$ 1.68	$ 1.62
Limited Partner and General Partner interests combined | Common units
Distributions
Partnership distribution	$ 55	$ 52	$ 110	$ 103

CHANGE IN OPERATING WORKING C45

CHANGE IN OPERATING WORKING CAPITAL (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CHANGE IN OPERATING WORKING CAPITAL
Change in accounts receivable and other	$ 4	$ 7
Change in accounts payable and accrued liabilities	(2)	4
Change in accounts payable to affiliates	(5)	17
Change in accrued interest	4
Change in operating working capital	$ 1	$ 28

CHANGE IN OPERATING WORKING C46

CHANGE IN OPERATING WORKING CAPITAL (Details 2) $ in Millions	6 Months Ended
	Jun. 30, 2015USD ($)
GTN
Non-cash items
Accruals for capital expenditures	$ 9

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Millions	Dec. 31, 2014	Apr. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	May. 03, 2015	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	Apr. 01, 2015	Oct. 01, 2014
Capital and operating costs charged to the pipeline systems and amount payable
Accounts payable to affiliates	$ 15		$ 10			$ 10		$ 15
Amount included in receivables from related party	1		1			1		1
Additional acquisition consideration relating to Carty Lateral project							$ 25
General Partner | Reimbursement of costs of services provided
Capital and operating costs charged to the pipeline systems and amount payable
Costs charged			1	$ 1		1	2
TransCanada's subsidiaries | Great Lakes
Capital and operating costs charged to the pipeline systems and amount payable
Accounts payable to affiliates	9		6			6		9
Amount included in receivables from related party	$ 15		30			30		15
TransCanada's subsidiaries | Great Lakes | Capital and operating costs
Capital and operating costs charged to the pipeline systems and amount payable
Costs charged			8	8		14	15
Impact on the Partnership's net income attributable to controlling interests			$ 3	$ 4		$ 6	$ 7
Percentage of capital and operating costs charged	100.00%		100.00%	100.00%		100.00%	100.00%
TransCanada's subsidiaries | Great Lakes | Transportation contracts
Capital and operating costs charged to the pipeline systems and amount payable
Revenues from related party			$ 18	$ 13		$ 47	$ 35
TransCanada's subsidiaries | Great Lakes | Transportation contracts | Total revenues | Major customers
Capital and operating costs charged to the pipeline systems and amount payable
Percent of total revenues			63.00%	43.00%		62.00%	46.00%
TransCanada's subsidiaries | Great Lakes | Affiliated rental revenue
Capital and operating costs charged to the pipeline systems and amount payable
Revenues from related party			$ 1	$ 1		$ 1	$ 1
TransCanada's subsidiaries | Northern Border
Capital and operating costs charged to the pipeline systems and amount payable
Accounts payable to affiliates	$ 10		6			6		10
TransCanada's subsidiaries | Northern Border | Capital and operating costs
Capital and operating costs charged to the pipeline systems and amount payable
Costs charged			9	10		16	17
Impact on the Partnership's net income attributable to controlling interests			$ 4	$ 4		$ 7	$ 7
Percentage of capital and operating costs charged	100.00%		100.00%	100.00%		100.00%	100.00%
TransCanada's subsidiaries | GTN
Capital and operating costs charged to the pipeline systems and amount payable
Accounts payable to affiliates	$ 10		$ 6			$ 6		10
TransCanada's subsidiaries | GTN | Capital and operating costs
Capital and operating costs charged to the pipeline systems and amount payable
Costs charged			8	$ 7		14	$ 13
Impact on the Partnership's net income attributable to controlling interests			7	$ 5		$ 11	$ 9
Percentage of capital and operating costs charged				100.00%		100.00%	100.00%
TransCanada's subsidiaries | Bison
Capital and operating costs charged to the pipeline systems and amount payable
Accounts payable to affiliates	2		1			$ 1		2
TransCanada's subsidiaries | Bison | Capital and operating costs
Capital and operating costs charged to the pipeline systems and amount payable
Costs charged			1	$ 1		2	$ 3
Impact on the Partnership's net income attributable to controlling interests			1	$ 1		2	$ 2
Percentage of capital and operating costs charged				100.00%			100.00%
TransCanada's subsidiaries | North Baja Pipeline, LLC
Capital and operating costs charged to the pipeline systems and amount payable
Accounts payable to affiliates	1		1			1		1
TransCanada's subsidiaries | North Baja Pipeline, LLC | Capital and operating costs
Capital and operating costs charged to the pipeline systems and amount payable
Costs charged			2	$ 1		3	$ 2
Impact on the Partnership's net income attributable to controlling interests			1	1		2	2
TransCanada's subsidiaries | Tuscarora Gas Transmission Company
Capital and operating costs charged to the pipeline systems and amount payable
Accounts payable to affiliates	$ 1		1			1		1
TransCanada's subsidiaries | Tuscarora Gas Transmission Company | Capital and operating costs
Capital and operating costs charged to the pipeline systems and amount payable
Costs charged			1	1		2	2
Impact on the Partnership's net income attributable to controlling interests			1	1		2	2
TransCanada's subsidiaries | Great Lakes
Capital and operating costs charged to the pipeline systems and amount payable
Revenue from TransCanada and its affiliates included in the Partnership's equity earnings			$ 8	$ 6		$ 22	$ 17
ANR Pipeline Company | Great Lakes | Firm service between Michigan and Wisconsin
Capital and operating costs charged to the pipeline systems and amount payable
Revenue deferred related to services performed					$ 14			$ 9.4
Former parent, TransCanada subsidiaries | Transaction between entities under common control | GTN
Capital and operating costs charged to the pipeline systems and amount payable
Interest acquired (as a percent)			30.00%	30.00%		30.00%	30.00%		30.00%
Additional acquisition consideration relating to Carty Lateral project		$ 25
Former parent, TransCanada subsidiaries | Transaction between entities under common control | Bison
Capital and operating costs charged to the pipeline systems and amount payable
Interest acquired (as a percent)										30.00%

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Millions	Jun. 30, 2015	Mar. 13, 2015	Dec. 31, 2014
Unsecured debt | 4.65% Senior Notes due 2021
Financial Instruments
Stated interest rate (as a percent)	4.65%		4.65%
Unsecured debt | 4.375% Senior Notes due 2025
Financial Instruments
Stated interest rate (as a percent)	4.375%	4.375%
Unsecured debt | 5.09% Senior Notes due 2015
Financial Instruments
Stated interest rate (as a percent)			5.09%
Unsecured debt | 5.29% Senior Notes due 2020
Financial Instruments
Stated interest rate (as a percent)	5.29%		5.29%
Unsecured debt | 5.69% Senior Notes due 2035
Financial Instruments
Stated interest rate (as a percent)	5.69%		5.69%
Secured debt | 3.82% Series D Senior Notes due 2017
Financial Instruments
Stated interest rate (as a percent)	3.82%		3.82%
Carrying Value
Financial Instruments
Debt	$ 1,914		$ 1,695
Carrying Value | Term loan | Short-Term Loan Facility due 2015
Financial Instruments
Debt	170		170
Carrying Value | Senior revolving credit facility | Senior Credit Facility due 2017
Financial Instruments
Debt	200		330
Carrying Value | Term loan | Term Loan Facility due 2018
Financial Instruments
Debt	500		500
Carrying Value | Unsecured debt | 4.65% Senior Notes due 2021
Financial Instruments
Debt	350		350
Carrying Value | Unsecured debt | 4.375% Senior Notes due 2025
Financial Instruments
Debt	349
Carrying Value | Unsecured debt | 5.09% Senior Notes due 2015
Financial Instruments
Debt			75
Carrying Value | Unsecured debt | Term Loan Facility due 2019
Financial Instruments
Debt	75
Carrying Value | Unsecured debt | 5.29% Senior Notes due 2020
Financial Instruments
Debt	100		100
Carrying Value | Unsecured debt | 5.69% Senior Notes due 2035
Financial Instruments
Debt	150		150
Carrying Value | Secured debt | 3.82% Series D Senior Notes due 2017
Financial Instruments
Debt	20		20
Fair Value | Level 2
Financial Instruments
Debt	1,942		1,751
Fair Value | Level 2 | Term loan | Short-Term Loan Facility due 2015
Financial Instruments
Debt	170		170
Fair Value | Level 2 | Senior revolving credit facility | Senior Credit Facility due 2017
Financial Instruments
Debt	200		330
Fair Value | Level 2 | Term loan | Term Loan Facility due 2018
Financial Instruments
Debt	500		500
Fair Value | Level 2 | Unsecured debt | 4.65% Senior Notes due 2021
Financial Instruments
Debt	364		375
Fair Value | Level 2 | Unsecured debt | 4.375% Senior Notes due 2025
Financial Instruments
Debt	347
Fair Value | Level 2 | Unsecured debt | 5.09% Senior Notes due 2015
Financial Instruments
Debt			76
Fair Value | Level 2 | Unsecured debt | Term Loan Facility due 2019
Financial Instruments
Debt	75
Fair Value | Level 2 | Unsecured debt | 5.29% Senior Notes due 2020
Financial Instruments
Debt	109		111
Fair Value | Level 2 | Unsecured debt | 5.69% Senior Notes due 2035
Financial Instruments
Debt	156		168
Fair Value | Level 2 | Secured debt | 3.82% Series D Senior Notes due 2017
Financial Instruments
Debt	$ 21		$ 21

FAIR VALUE MEASUREMENTS (Deta49

FAIR VALUE MEASUREMENTS (Details 2) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Interest rate swaps from September 3, 2013 through July 1, 2018 | Term loan | Term Loan Facility due 2018
Interest rate derivatives
Amount of variable-rate debt hedged	$ 150		$ 150
Weighted average fixed interest rate (as a percent)	2.79%		2.79%
Interest rate swaps
Interest rate derivatives
Amount recorded in net income related to ineffectiveness for interest rate hedges		$ 0		$ 0
Hedges of cash flows | Interest rate swaps
Interest rate derivatives
Change in fair value of interest rate derivative instruments recognized in other comprehensive income	$ 0	1	$ 1	1
Hedges of cash flows | Interest rate swaps | Financial charges and other
Interest rate derivatives
Net realized loss related to the interest rate swaps	0	$ 1	1	$ 1
Designated as hedge | Interest rate swaps | Recurring fair value measurement | Level 2
Interest rate derivatives
Fair value of derivatives, gross	2		2		$ 1
Fair value of derivatives, net	$ 2		$ 2		$ 1

ACCOUNTS RECEIVABLE AND OTHER50

ACCOUNTS RECEIVABLE AND OTHER (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
ACCOUNTS RECEIVABLE AND OTHER
Trade accounts receivable, net of allowance of nil	$ 28	$ 30
Accounts receivable from affiliates	1	1
Other	4	4
Accounts receivable and other	33	35
Trade accounts receivable, allowance	$ 0	$ 0

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - USD ($) $ / shares in Units, $ in Millions	Aug. 03, 2015	Jul. 23, 2015	Jul. 22, 2015	Jun. 30, 2015	Mar. 31, 2015
Northern Border
Distributions
Ownership interest (as a percent)				50.00%
Great Lakes
Distributions
Ownership interest (as a percent)				46.45%	46.45%
Subsequent event | Distribution declared | Northern Border
Distributions
Partnership distribution			$ 42
Subsequent event | Distribution declared | Great Lakes
Distributions
Partnership distribution			$ 7
Subsequent event | Cash Distribution Paid | Northern Border
Distributions
Partnership's share of distributions	$ 21
Subsequent event | Cash Distribution Paid | Great Lakes
Distributions
Partnership's share of distributions	$ 3
Subsequent event | Common units
Distributions
Cash distribution (in dollars per unit)		$ 0.89