SHARE PLEDGE AGREEMENT

Exhibit 10.8

SHARE PLEDGE AGREEMENT

      THIS AGREEMENT, dated as of February 22, 2007 (as amended, supplemented, amended and restated or otherwise modified from time to time, this " Agreement "),

BETWEEN:

GRAN TIERRA ENERGY INC., a corporation organized under the laws of the State of Nevada (the " Pledgor ")

- and -

STANDARD BANK PLC, in its capacity as administrative agent under the Credit Agreement (as hereinafter defined) acting for and on behalf of the Secured Parties (in such capacity, the " Pledgee ").

RECITALS:

      NOW, THEREFORE, in consideration of the premises and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Pledgor hereby agrees as follows:

(a) Definition of Terms Used Herein . Capitalized terms used but not defined herein shall have the meanings assigned to them in the Credit Agreement. In addition:

(i) " Bylaws " means the bylaws of the Issuer, or such other analogous agreement governing its operation.

(ii) " Issuer " has the meaning set forth in the recitals hereto.

(iii) " Obligations " means the principal of and interest on the Loans made by the Banks to, and the Notes held by each Bank from, and Reimbursement Obligations in respect of Letters of Credit issued for the account of, and the Designated Hedging Obligations of, the Pledgor and all other amounts from time to time owing to the Secured Parties by the Pledgor under the Credit Agreement, under the Notes, under each Designated Hedging Agreement and by any Obligor under any of the other Loan Documents to which such Obligor is a party, in each case strictly in accordance with the terms hereof and thereof.

(iv) " PPSA " means the Personal Property Security Act (Alberta), R.S.A. 2000 c. P-7, as amended.

(v) " Pledged Interests " means 65% of the total issued share capital (less such share, not to exceed 1 per cent., as may be required to avoid the giving of any fractions of a share as security) held by the Pledgor in the Issuer now or in the future owned by it, or (to the extent of its interest) in which it now or in the future has an interest, being at the date of this Agreement, 65 common shares without par value.

(vi) " Pledged Property " has the meaning set forth in Section 2(a) hereto.

(a) As collateral security for the prompt performance, observance and indefeasible payment in full of all the Obligations, the Pledgor hereby assigns and pledges to the Pledgee, and grants to the Pledgee for itself and the benefit of the Secured Parties, a security interest in and Lien upon the following (collectively, the " Pledged Property "):

(i) the Pledged Interests and all certificates (if any) at any time representing or evidencing the Pledged Interests;

(ii) all of its present and future right to receive payment of money or other distributions arising out of or in connection with the Pledged Interests;

(iii) all proceeds of and to any of the property of the Pledgor described above, including, without limitation, all causes of action, claims and warranties now or hereafter held by the Pledgor in respect of any of the items listed above; and

(iv) the Pledgor’s books and records with respect to any of the foregoing.

(b) [Intentionally Omitted]

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(a) The Lien and other interests granted to the Pledgee for itself and the benefit of the Secured Parties, pursuant to this Agreement shall secure the prompt performance and payment in full of any and all of the Obligations.

(b) The Pledgor shall deposit with the Pledgee all certificates representing the Pledged Interests. All certificates deposited pursuant to this section 3(b) shall not contain any reference to restrictions on the transfer of the Pledged Interests represented thereby and shall be accompanied by a duly executed stock power transfer.

     The Pledgor hereby represents, warrants and covenants with and to the Pledgee and the Secured Parties the following as of the date hereof (all of such representations, warranties and covenants being continuing so long as any of the Obligations are outstanding):

(a) The Pledged Interests are duly authorized and validly existing and constitute 65 per cent of the Pledgor’s ownership interest in the Issuer and the Pledgor is the registered owner of the Pledged Interests.

(b) The Pledgor is the holder of all of the ownership interests in the Issuer.

(c) The Pledged Property pledged by the Pledgor hereunder is directly, legally and beneficially owned by the Pledgor free and clear of all claims and Liens of any kind, nature or description, other than those created pursuant to this Agreement in favor of the Pledgee (for itself and for the benefit of the Secured Parties) and other than Permitted Liens.

(d) The Pledged Property pledged by the Pledgor hereunder is not subject to any restriction relative to the transfer thereof (other than applicable law) and the Pledgor has the right to transfer the Pledged Property free and clear of any Lien other than Permitted Liens;

(e) The Pledged Property pledged by the Pledgor hereunder is duly and validly pledged to the Pledgee, no consent or approval of any governmental or regulatory authority or of any securities exchange or the like, nor any consent or approval of any other third party, was or is necessary to the validity and enforceability of this Agreement, except as expressly set forth herein (other than applicable securities laws which will apply in connection with an exercise of remedies hereunder).

(f) If the Pledgor shall become entitled to receive or acquire, or shall receive any ownership interest certificate, or option or right with respect to the Pledged Interests (including without limitation, any certificate representing a distribution or exchange of or in connection with reclassification of the Pledged Interests) whether as an addition to, in substitution of, or in exchange for any of the Pledged Property or otherwise, the Pledgor agrees to accept the same as the Pledgee’s agent, to hold the same in trust for the Pledgee and to deliver the same forthwith to

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the Pledgee or the Pledgee’s agent or bailee in the form received, with the endorsement(s) of the Pledgor where necessary and/or appropriate powers and/or assignments duly executed to be held by the Pledgee or the Pledgee’s agent or bailee subject to the terms hereof, as further security for the Obligations.

(g) As of the date hereof, the Pledged Interests pledged by the Pledgor hereunder are represented by Share Certificate No. C-2.

(h) The Pledgor shall keep full and accurate books and records relating to the Pledged Property pledged by the Pledgor hereunder and stamp or otherwise mark such books and records in such manner as the Pledgee may in good faith require in order to reflect the security interests granted by this Agreement.

(i) The Pledgor shall not, without the prior consent of the Pledgee, directly or indirectly, sell, assign, transfer, or otherwise dispose of, or grant any option with respect to the Pledged Property, nor shall the Pledgor create, incur or permit any further Lien with respect to the Pledged Property other than as permitted in the Credit Agreement.

(j) So long as no Event of Default has occurred and is continuing, the Pledgor shall have the right to exercise all rights with respect to the Pledged Property, except as expressly prohibited herein or in the other Loan Documents, and to receive any distributions payable in respect of the Pledged Property (but subject to terms of the Credit Agreement with respect thereto).

(k) The Pledgor has delivered to the Pledgee a true, correct and complete copy of the bylaws of the Issuer. There are and, unless as permitted under the Credit Agreement, shall be no other agreements governing the formation, organization or terms of the ownership interests with respect to the Issuer.

(l) Other than as permitted in the Credit Agreement, the Pledgor shall not permit the Issuer, directly or indirectly, to (i) issue, sell, grant, assign, transfer or otherwise dispose of, any additional ownership interests of such Issuer or any option or warrant with respect to, or other right or security convertible into, any additional ownership interests, now or hereafter authorized, unless 65% of such additional ownership interests, options, warrants, rights or other such securities are made and shall remain part of the Pledged Property subject to the pledge and security interest granted herein, or (ii) take any action to withdraw the authority of or to limit or restrict the authority of such Issuer’s directors or officers to deal and contract with the Pledgee and to bind and obligate such Issuer.

(m) [Intentionally Omitted]

(n) The Pledgor shall not, and shall not permit the Issuer, directly or indirectly, to, amend, modify or supplement any of the provisions of the Bylaws or the Issuer’s articles of incorporation without the prior written consent of the Pledgee if any such amendment, modification or

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supplement could reasonably be expected to affect any rights of the Pledgee or any Secured Party hereunder or under any of the other Loan Documents, or would limit or restrict the permissible activities in which the Issuer may engage.

(o) [Intentionally Omitted]

(p) The Pledgor shall furnish, or cause to be furnished, to the Pledgee such information concerning the Issuer and the Pledged Property as the Pledgee may from time to time reasonably request.

(q) The Pledgee may notify the Issuer or the appropriate transfer agent of the Pledged Interests to register on the books of such Issuer the security interest and pledge granted herein and honor the rights of the Pledgee and the Secured Parties with respect thereto.

(r) The Pledgor shall not change its name or its jurisdiction of organization from that existing as of the date of this Agreement, except upon 15 Business Days’ prior written notice to the Pledgee and delivery to the Pledgee of copies of all filed additional financing statements, and other documents (in each case, properly executed) reasonably requested by the Pledgee to maintain the validity, perfection and priority of the security interests provided for herein.

(s) The Pledgor agrees that the Pledged Property, other collateral, or any guarantor or endorser may be released, substituted or added with respect to the Obligations, in whole or in part, without releasing or otherwise affecting the liability of the Pledgor, the pledge and security interests granted hereunder, or this Agreement.

     At any time after an Event of Default exists or has occurred and is continuing, in addition to all other rights and remedies of the Pledgee and the Secured Parties, whether provided under this Agreement, the Credit Agreement, the other Loan Documents, applicable law or otherwise, the Pledgee shall have the following rights and remedies which may be exercised without notice to, or consent by, the Pledgor except as such notice or consent is expressly provided for hereunder or such notices which the Pledgor may not waive in accordance with applicable law:

(a) The Pledgee, at its option, shall be empowered to exercise its continuing right to instruct the Issuer in