Gran Tierra Energy (GTE) 10-K/A 2010 FY Annual report (amended)

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A
Amendment No. 1

(Mark One)

x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the year ended December 31, 2010

OR

o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from _____________ to _____________

Commission File Number 001-34018

GRAN TIERRA ENERGY INC.

(Exact name of registrant as specified in its charter)

Nevada	98-0479924
(State or other jurisdiction of  incorporation or organization)	(I.R.S. Employer Identification No.)

300, 625 11th Avenue SW

Calgary, Alberta, Canada T2R 0E1

(Address of principal executive offices, including zip code)

(403) 265-3221

(Registrant’s telephone number, including area code)  

Securities Registered Pursuant to Section 12(b) of the Act:

Title of Each Class	Name of Each Exchange on Which Registered
Common Stock, par value $0.001 per share	NYSE Amex
	Toronto Stock Exchange

Securities Registered Pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes xNo ¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ¨No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes xNo ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes x No ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer xAccelerated filer ¨Non-accelerated filer ¨ (do not check if a smaller reporting company)Smaller reporting company ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨No x

The aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold as of the last business day of the registrant’s most recently completed second fiscal quarter was approximately $1,197,806,292 (including shares issuable upon exercise of exchangeable shares). Aggregate market value excludes an aggregate of 1,101,633 shares of common stock and 11,125,525 shares issuable upon exercise of exchangeable shares held by officers and directors and by each person known by the registrant to own 10% or more of the outstanding common stock on such date. Exclusion of shares held by any of these persons should not be construed to indicate that such person possesses the power, direct or indirect, to direct or cause the direction of the management or policies of the registrant, or that such person is controlled by or under common control with the registrant.

On February 18, 2011, the following numbers of shares of the registrant’s capital stock were outstanding: 240,857,632 shares of the registrant’s Common Stock, $0.001 par value; one share of Special A Voting Stock, $0.001 par value,  representing 7,811,112 shares of Gran Tierra Goldstrike Inc., which are exchangeable on a 1-for-1 basis into the registrant’s Common Stock; and  one share of Special B Voting Stock, $0.001 par value,  representing 9,539,042 shares of Gran Tierra Exchangeco Inc., which are exchangeable on a 1-for-1 basis into the registrant’s Common Stock.

DOCUMENTS INCORPORATED BY REFERENCE

The information required by Part III of this report, to the extent not set forth herein, is incorporated by reference from the Registrant’s definitive proxy statement relating to the 2011 annual meeting of stockholders, which definitive proxy statement will be filed with the Securities and Exchange Commission within 120 days after the fiscal year to which this Report relates.

EXPLANATORY NOTE

This Amendment No. 1 to Form 10-K is being filed to revise the Exhibit Index to include therein the list of XBRL documents submitted with the Form 10-K.

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SIGNATURES

Pursuant to the requirements of section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

		GRAN TIERRA ENERGY INC.
Date:	February 28, 2011	By:	/s/ Dana Coffield
			Dana Coffield
			Chief Executive Officer and President
			(Principal Executive Officer)
Date:	February 28, 2011	By:	/s/ Martin Eden
			Martin Eden
			Chief Financial Officer
			(Principal Financial and Accounting Officer)

  

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated:

Name	Title	Date
/s/ Dana Coffield	Chief Executive Officer and President	February 28, 2011
Dana Coffield	(Principal Executive Officer)
/s/ Martin Eden	Chief Financial Officer	February 28, 2011
Martin Eden	(Principal Financial and Accounting Officer)
*	Chairman of the Board, Director	February 28, 2011
Jeffrey Scott
*	Director	February 28, 2011
Verne Johnson
*	Director	February 28, 2011
Nicholas G. Kirton
*	Director	February 28, 2011
J. Scott Price
*	Director	February 28, 2011
Ray Antony
*	Director	February 28, 2011
Gerry Macey

* By:	/s/ Dana Coffield
	Dana Coffield
	Attorney-in-Fact

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EXHIBIT INDEX

Exhibit No.	Description	Reference
2.1	Arrangement Agreement, dated as of July 28, 2008, by and among Gran Tierra Energy Inc., Solana Resources Limited and Gran Tierra Exchangeco Inc.	Incorporated by reference to Exhibit 2.1 to the Current Report on Form 8-K, filed with the SEC on August 1, 2008 (File No. 001-34018).
2.2	Amendment No. 2 to Arrangement Agreement, which includes the Plan of Arrangement, including appendices.	Incorporated by reference to Exhibit 2.2 to the Registration Statement on Form S-3 (Reg. No. 333-153376), filed with the SEC on October 10, 2008 (File No. 001-34018).
2.3	Arrangement Agreement, dated January 17, 2011, by and between Gran Tierra Energy Inc. and Petrolifera Petroleum Limited.	Incorporated by reference to Exhibit 2.1 to the Current Report on Form 8-K, filed with the SEC on January 21, 2011 (File No. 001-34018).
3.1	Amended and Restated Articles of Incorporation.	Incorporated by reference to Exhibit 3.1 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No. 001-34018).
3.2	Fifth Amended and Restated Bylaws of Gran Tierra Energy Inc.	Incorporated by reference to Exhibit 3.1 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on September 22, 2008 (File No. (File No. 001-34018).
4.1	Reference is made to Exhibits 3.1 and 3.2.
4.2	Form of Warrant issued to institutional and retail investors in connection with the private offering in June 2006.	Incorporated by reference to Exhibit 4.2 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on June 21, 2006 (File No. 333-111656).
4.3	Details of the Goldstrike Special Voting Share.	Incorporated by reference to Exhibit 10.14 to the Annual Report on Form 10-KSB/A for the period ended December 31, 2005 and filed with the Securities and Exchange on April 21, 2006 (File No. 333-111656).
4.4	Goldstrike Exchangeable Share Provisions.	Incorporated by reference to Exhibit 10.15 to the Annual Report on Form 10-KSB/A for the period ended December 31, 2005 and filed with the Securities and Exchange on April 21, 2006 (File No. 333-111656).
4.5	Provisions Attaching to the GTE–Solana Exchangeable Shares.	Incorporated by reference to Annex E to the Proxy Statement on Schedule 14A filed with the Securities and Exchange Commission on October 14, 2008 (File No. 001-34018).
4.6	Reference is made to Exhibits 10.1 through 10.11 below.
10.1	Form of Registration Rights Agreement by and among Goldstrike Inc. and the purchasers named therein.	Incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on December 19, 2005 (File No. 333-111656).

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10.2	Form of Registration Rights Agreement by and among Goldstrike Inc. and the purchasers named therein.	Incorporated by reference to Exhibit 10.32 to Form SB-2, as amended, filed with the Securities and Exchange Commission on December 7, 2006 (File No. 333-111656).
10.3	Form of Registration Rights Agreement by and among Gran Tierra Energy, Inc. f/k/a Goldstrike, Inc. and the purchasers named therein.	Incorporated by reference to Exhibit 10.34 to Form SB-2, as amended, filed with the Securities and Exchange Commission on December 7, 2006 (File No. 333-111656).
10.4	Form of Registration Rights Agreement, dated as of June 20, 2006, by and among Gran Tierra Energy Inc. and institutional investors purchasing units of Gran Tierra Energy Inc. securities in a private offering.	Incorporated by reference to Exhibit 10.23 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on June 21, 2006 (File No. 333-111656).
10.5	Form of Registration Rights Agreement, dated as of June 20, 2006, by and among Gran Tierra Energy Inc. and retail investors purchasing units of Gran Tierra Energy Inc. securities in a private offering.	Incorporated by reference to Exhibit 10.24 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on June 21, 2006 (File No. 333-111656).
10.6	Registration Rights Agreement, dated as of June 20, 2006, by and between Gran Tierra Energy Inc. and CD Investment Partners, Ltd.	Incorporated by reference to Exhibit 10.25 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on June 21, 2006 (File No. 333-111656).
10.7	Registration Rights Agreement, dated as of June 20, 2006, by and between Gran Tierra Energy Inc. and Crosby Capital, LLC.	Incorporated by reference to Exhibit 10.27 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on June 21, 2006 (File No. 333-111656).
10.8	Form of Registration Rights Agreement, dated as of June 30, 2006, by and among Gran Tierra Energy Inc. and the investors in the June 30, 2006 closing of the Offering.	Incorporated by reference to Exhibit 10.30 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on July 5, 2006 (File No. 333-111656).
10.9	Voting Exchange and Support Agreement by and between Goldstrike, Inc., 1203647 Alberta Inc., Gran Tierra Goldstrike Inc. and Olympia Trust Company dated as of November 10, 2005.	Incorporated by reference to Exhibit 10.3 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on November 10, 2005 (File No. 333-111656).
10.10	Voting and Exchange Trust Agreement, dated as of November 14, 2008, between Gran Tierra Energy Inc., Gran Tierra Exchangeco Inc. and Computershare Trust Company of Canada.	Incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on November 17, 2008 (File No. 001-34018).
10.11	Support Agreement, dated as of November 14, 2008, between Gran Tierra Energy Inc., Gran Tierra Callco ULC and Gran Tierra Exchangeco Inc.	Incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K, filed with the SEC on November 17, 2008 (File No. 001-34018).
10.12	2007 Equity Incentive Plan.*	Incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 6, 2010 (File No. 001-34018).
10.13	Form of Option Agreement under the Company’s 2007 Equity Incentive Plan.*	Incorporated by reference to Exhibit 99.1 to the current report on Form 8-K filed with the Securities and Exchange Commission on December 21, 2007 (File No. 000-52594).
10.14	Form of Grant Notice under the Company’s 2007 Equity Incentive Plan.*	Incorporated by reference to Exhibit 99.2 to the current report on Form 8-K filed with the Securities and Exchange Commission on December 21, 2007 (File No. 000-52594).
10.15	Form of Exercise Notice under the Company’s 2007 Equity Incentive Plan.*	Incorporated by reference to Exhibit 99.3 to the current report on Form 8-K filed with the Securities and Exchange Commission on December 21, 2007 (File No. 000-52594).

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10.16	Form of Indemnity Agreement. *	Incorporated by reference to Exhibit 99.1 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on April 2, 2008 (File No.  000-52594).
10.17	2005 Equity Incentive Plan. *	Incorporated by reference to Exhibit 10.11 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on November 10, 2005 (File No. 333-111656).
10.18	2008 Executive Officer Cash Bonus Compensation and 2009 Cash Compensation*	Incorporated by reference to Item 5.02 of the Current Report on Form 8-K, filed with the SEC on December 17, 2008 (File No. 001-34018).
10.19	2009 Executive Officer Cash Bonus Compensation and 2010 Cash Compensation*	Incorporated by reference to Item 5.02 of the Current Report on Form 8-K, filed with the SEC on February 18, 2010 (File No. 001-34018).
10.20	Employment Agreement, dated November 4, 2008, between Gran Tierra Energy Inc. and Dana Coffield.*	Incorporated by reference to Exhibit 10.57 to the Annual Report on Form 10-K, filed with the SEC on February 27, 2009 (File No. 001-34018).
10.21	Employment Agreement, dated June 17, 2008, between Gran Tierra Energy Inc. and Martin Eden. *	Incorporated by reference to Exhibit 10.58 to the Quarterly Report on Form 10-Q, filed with the SEC on August 11, 2008 (File No. 001-34018).
10.22	Employment Agreement, dated June 17, 2008, between Gran Tierra Energy Inc. and Rafael Orunesu.*	Incorporated by reference to Exhibit 10.61 to the Quarterly Report on Form 10-Q, filed with the SEC on August 11, 2008 (File No. 001-34018).
10.23	Employment Agreement, dated November 23, 2009, between Gran Tierra Energy Inc. and Julian Garcia *	Incorporated by reference to Exhibit 10.23 to the Quarterly Report on Form 10-Q, filed with the SEC on August 11, 2008 (File No. 001-34018).
10.24	Offer Letter between Gran Tierra Energy Inc. and Shane P. O’Leary dated January 26, 2009 *	Incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K, filed with the SEC on February 4, 2009 (File No. 001-34018).
10.25	Employment Agreement between Gran Tierra Energy Inc. and Shane P. O’Leary dated as of January 26, 2009. *	Incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K, filed with the SEC on February 4, 2009 (File No. 001-34018).
10.26	Employment Agreement, dated July 1, 2009, between Gran Tierra Energy Inc. and Julio César Moreira.*	Incorporated by reference to Exhibit 10.62 to the Annual Report on Form 10-K for the period ended December 31, 2009 and filed with the Securities and Exchange on February 26, 2010 (File No.  001-34018).
10.27	Colombian Participation Agreement, dated as of June 22, 2006, by and among Argosy Energy International, Gran Tierra Energy Inc., and Crosby Capital, LLC.	Incorporated by reference to Exhibit 10.55 to the Quarterly Report on Form 10-Q, filed with the SEC on August 11, 2008 (File No.  333-111656).
10.28	Amendment No. 1 to Colombian Participation Agreement, dated as of November 1, 2006, by and among Argosy Energy International, Gran Tierra Energy Inc., and Crosby Capital, LLC.	Incorporated by reference to Exhibit 10.56 to the Quarterly Report on Form 10-Q, filed with the SEC on August 11, 2008 (File No.  001-34018).
10.29	Amendment No. 2 to Colombian Participation Agreement, dated as of July 3, 2008, between Gran Tierra Energy Inc. and Crosby Capital, LLC.	Incorporated by reference to Exhibit 10.3 to the Quarterly Report on Form 10-Q/A, filed with the SEC on November 19, 2008 (File No.  001-34018).
10.30	Amendment No. 3 to Participation Agreement, dated as of December 31, 2008, by and among Gran Tierra Energy Colombia, Ltd., Gran Tierra Energy Inc. and Crosby Capital, LLC.	Incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K, filed with the SEC on January 7, 2009 (File No.  001-34018).

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10.31	Form of Voting Support Agreement Respecting the Arrangement Involving Petrolifera Petroleum Limited and  Gran Tierra Energy Inc. (Petrolifera Directors and Officers)	Incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K, filed with the SEC on January 21, 2011 (File No.  001-34018).
10.32	Form of Voting Support Agreement Respecting the Arrangement Involving Petrolifera Petroleum Limited and Gran Tierra Energy Inc. (Petrolifera largest stockholder)	Incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K, filed with the SEC on January 21, 2011 (File No.  001-34018).
10.33	Assignment and Assumption Agreement, dated as of August 24, 2009, by and among Gran Tierra Energy Inc., Gran Tierra Energy Cayman Islands Inc., and Standard Bank PLC.	Incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.34	Amended and Restated Credit Agreement, dated as of August 24, 2009, by and among Gran Tierra Energy Inc., Gran Tierra Energy Colombia, Ltd., Argosy Energy, LLC, Solana Petroleum Exploration (Colombia) Limited, Solana Resources Limited, and Standard Bank PLC.	Incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.35	First Priority Open Pledge Agreement over Credit Rights Derived from Hydrocarbon Commercial Sales Agreements, dated as of August 24, 2009, by and between Solana Petroleum Exploration (Colombia) Limited and Standard Bank PLC.	Incorporated by reference to Exhibit 10.3 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.36	First Priority Open Pledge Agreement over a Commercial Establishment, dated as of August 24, 2009, by and between Solana Petroleum Exploration (Colombia) Limited and Standard Bank PLC.	Incorporated by reference to Exhibit 10.4 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.37	Amended and Restated First Priority Open Pledge Agreement over Credit Rights Derived from Crude Oil Commercial Sales Agreements, dated as of August 24, 2009, by and between Gran Tierra Energy Colombia, Ltd., and Standard Bank PLC.	Incorporated by reference to Exhibit 10.5 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.38	Cancellation of BNP Pledge over Credit Rights, dated as of August 20, 2009, by BNP Paribas.	Incorporated by reference to Exhibit 10.6 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.39	Cancellation of BNP Pledge over Commercial Establishment, dated as of August 21, 2009, by BNP Paribas.	Incorporated by reference to Exhibit 10.7 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.40	Collection Account Pledge Agreement, dated as of August 24, 2009, by and between Solana Petroleum Exploration (Colombia) Limited and Standard Bank PLC.	Incorporated by reference to Exhibit 10.8 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.41	Deposit Account Control Agreement, dated as of August 24, 2009, by and among Solana Petroleum Exploration (Colombia) Limited, BNP Paribas, and Standard Bank PLC.	Incorporated by reference to Exhibit 10.9 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.42	Letter regarding Pledge Agreements, dated as of August 24, 2009, by and among the Gran Tierra Energy Cayman Islands Inc, Gran Tierra Energy Colombia, Ltd., Argosy Energy, LLC, GTE Colombia Holdings LLC, and Standard Bank PLC.	Incorporated by reference to Exhibit 10.10 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).
10.43	Release of Share Pledge Agreement, dated as of August 24, 2009, by and between Gran Tierra Energy Inc. and Standard Bank PLC.	Incorporated by reference to Exhibit 10.11 to the Quarterly Report on Form 10-Q/A, filed with the SEC on January 6, 2010 (File No.  001-34018).

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10.44	Credit Agreement, dated as of July 30, 2010, among Solana Resources Limited, Gran Tierra Energy Inc., the Lenders party thereto, and BNP Paribas.	Incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on August 5, 2010 (File No. 001-34018).
10.45	First Amendment to Credit Agreement, dated as of August 30, 2010, among Solana Resources Limited, Gran Tierra Energy Inc., BNP Paribas and Other Lenders	Incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 5, 2010 (File No. 001-34018).
10.46	Second Amendment to Credit Agreement, dated as of November 5, 2010, among Solana Resources Limited, Gran Tierra Energy Inc., BNP Paribas and Other Lenders	Previously filed with the Form 10-K to which this Form 10-K/A relates.
10.47	Third Amendment to Credit Agreement, dated as of January 20, 2011, among Solana Resources Limited, Gran Tierra Energy Inc., BNP Paribas and Other Lenders	Previously filed with the Form 10-K to which this Form 10-K/A relates.
10.48	Agreement between Gran Tierra Colombia Ltd. and Ecopetrol S.A., dated December 17, 2009, and accepted December 18, 2009, with respect to the sale of crude oil from the Chaza Block.	Incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on November 15, 2010 (File No. 001-34018).
10.49	Amendment No. 1, executed November 8, 2010, to Agreement between Gran Tierra Colombia Ltd. and Ecopetrol S.A., dated December 17, 2009 and accepted December 18, 2009, with respect to the sale of crude oil from the Chaza Block.	Incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed with the Securities and Exchange Commission on November 15, 2010 (File No. 001-34018).
10.50	Addendum, entered into between Gran Tierra Colombia Ltd. and Ecopetrol S.A. on December 30, 2010, amending the Agreement between those parties dated December 17, 2009 and accepted December 18, 2009, with respect to the sale of crude oil from the Chaza Block.	Previously filed with the Form 10-K to which this Form 10-K/A relates.
10.51	Agreement between Solana Petroleum Exploration Colombia Ltd. and Ecopetrol S.A., dated December 17, 2009, and accepted December 18, 2009, with respect to the sale of crude oil from the Chaza Block.	Previously filed with the Form 10-K to which this Form 10-K/A relates.
10.52	Amendment No. 1, executed November 8, 2010, to Agreement between Solana Petroleum Exploration Colombia Ltd. and Ecopetrol S.A., dated December 17, 2009 and accepted December 18, 2009, with respect to the sale of crude oil from the Chaza Block	Previously filed with the Form 10-K to which this Form 10-K/A relates.
10.53	Addendum, entered into between  Solana Petroleum Exploration Colombia Ltd. and Ecopetrol S.A. on December 30, 2010, amending the Agreement between those parties dated December 17, 2009 and accepted December 18, 2009, with respect to the sale of crude oil from the Chaza Block.	Previously filed with the Form 10-K to which this Form 10-K/A relates.
21.1	List of subsidiaries.	Previously filed with the Form 10-K to which this Form 10-K/A relates.
23.1	Consent of Deloitte & Touche LLP	Previously filed with the Form 10-K to which this Form 10-K/A relates.
23.2	Consent of GLJ Petroleum Consultants	Previously filed with the Form 10-K to which this Form 10-K/A relates.
24.1	Power of Attorney.	Previously filed with the Form 10-K to which this Form 10-K/A relates.
31.1	Certification of Principal Executive Officer	Previously filed with the Form 10-K to which this Form 10-K/A relates, and filed herewith with respect to this Form 10-K/A.
31.2	Certification of Principal Financial Officer	Previously filed with the Form 10-K to which this Form 10-K/A relates, and filed herewith with respect to this Form 10-K/A.
32.1	Certification of Principal Executive and Financial Officers	Previously filed with the Form 10-K to which this Form 10-K/A relates.

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99.1	Gran Tierra Energy Inc. Reserves Assessment and Evaluation of Argentine and Colombian Oil and Gas Properties Corporate Summary, effective December 31, 2010	Previously filed with the Form 10-K to which this Form 10-K/A relates.
101.INS†	XBRL Instance Document
101.SCH†	XBRL Taxonomy Extension Schema Document
101.CAL†	XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF†	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB†	XBRL Taxonomy Extension Label Linkbase Document
101.PRE†	XBRL Taxonomy Extension Presentation Linkbase Document

† XBRL information is furnished and not filed for purposes of Sections 11 and 12 of the Securities Act of 1933 and Section 18 of the Securities Exchange Act of 1934, and is not subject to liability under those sections, is not part of any registration statement or prospectus to which it relates and is not incorporated or deemed to be incorporated by reference into any registration statement, prospectus or other document.

* Management contract or compensatory plan or arrangement.

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