Exhibit
      10.2

    


    SUPPORT
      AGREEMENT

     

    SUPPORT
      AGREEMENT
      (the
“Agreement”)
      made
      as of the 14th
      day of
      November, 2008.

     

    AMONG:

     

    GRAN
      TIERRA ENERGY INC.,
      a
      corporation existing under the laws of the State of Nevada (hereinafter referred
      to as “Acquiror”),

     

    -
      and
      -

     

    GRAN
      TIERRA CALLCO ULC,
      a
      corporation existing under the laws of the Province of Alberta (hereinafter
      referred to as “Callco”),

     

    -
      and
      -

     

    GRAN
      TIERRA EXCHANGECO INC.,
      an
      indirect wholly-owned subsidiary of Acquiror, existing under the laws of the
      Province of Alberta (hereinafter referred to as “ExchangeCo”),

     

    WHEREAS,
      in
      connection with an arrangement agreement (the “Arrangement
      Agreement”)
      made
      as of July 28, 2008 among Acquiror, ExchangeCo and Solana Resources Limited,
      a
      corporation existing under the laws of Alberta (“Target”),
      ExchangeCo is to issue exchangeable shares (the “Exchangeable
      Shares”)
      to
      certain holders of common shares in the capital of Target (“Target
      Common Shares”)
      pursuant to the plan of arrangement (the “Arrangement”)
      contemplated by the Arrangement Agreement;

     

    AND
      WHEREAS,
      pursuant to the Arrangement Agreement, Acquiror and ExchangeCo have agreed
      to
      execute a support agreement substantially in the form of this Agreement on
      the
      Effective Date (as defined in the Arrangement Agreement);

     

    NOW
      THEREFORE,
      in
      consideration of the respective covenants and agreements provided in this
      Agreement and for other good and valuable consideration (the receipt and
      sufficiency of which are hereby acknowledged), the parties hereto covenant
      and
      agree as follows:

     

    ARTICLE
      1

    INTERPRETATION

     

    1.1 Defined
      Terms

     

    Each
      term
      denoted herein by initial capital letters and not otherwise defined herein
      shall
      have the meaning ascribed thereto in the rights, privileges, restrictions and
      conditions (collectively, the “Exchangeable
      Share Provisions”)
      attaching to the Exchangeable Shares which are attached as Schedule “A” to the
      Plan of Arrangement which is attached as Exhibit A to the Arrangement Agreement
      and as set out in the Articles of Arrangement of Target, unless the context
      requires otherwise.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    1.2 Interpretation
      Not Affected by Headings

     

    The
      division of this agreement into articles, sections, subsections and other
      portions and the insertion of headings are for convenience of reference only
      and
      shall not affect the construction or interpretation hereof. Unless otherwise
      indicated, all references to an “Article”, “Section” or “Subsection” followed by
      a number refer to the specified Article, Section or Subsection of this
      Agreement. The terms “this Agreement,” “hereof,” “herein” and “hereunder” and
      similar expressions refer to this Agreement and not to any particular Article,
      Section, Subsection or other portion hereof.

     

    1.3 Rules
      of Construction

     

    Unless
      otherwise specifically indicated or the context otherwise requires: (a) all
      references to “dollars” or “$” mean United States dollars; (b) words importing
      the singular shall include the plural and vice versa and words importing any
      gender shall include all genders; and (c) “include,” “includes” and “including”
shall be deemed to be followed by the words “without limitation.”

     

    1.4 Date
      for any Action

     

    If
      the
      event that any date on which any action is required to be taken hereunder by
      any
      of the parties hereto is not a Business Day, such action shall be required
      to be
      taken on the next succeeding day that is a Business Day.

     

    ARTICLE
      2

    COVENANTS
      OF ACQUIROR AND EXCHANGECO

     

    2.1 Covenants
      Regarding Exchangeable Shares

     

    So
      long
      as any Exchangeable Shares not owned by Acquiror or its Affiliates are
      outstanding, Acquiror will:

     

    
      	 	
              (a)

            	
              not
                declare or pay any dividend on common shares in the capital of Acquiror
                (“Acquiror
                Common Shares”)
                unless: (i) ExchangeCo shall: (a) simultaneously declare or pay,
                as the
                case may be, an equivalent dividend or other distribution economically
                equivalent thereto (as provided for in the Exchangeable Share Provisions)
                on the Exchangeable Shares (an “Equivalent
                Dividend”);
                and (b) ExchangeCo shall have sufficient money or other assets or
                authorized but unissued securities available to enable the due declaration
                and the due and punctual payment, in accordance with applicable law,
                of
                any such Equivalent Dividend; or (ii) if the dividend or other
                distribution is a stock dividend or distribution of stock, in lieu
                of such
                dividend ExchangeCo shall: (a) effect a corresponding, contemporaneous
                and
                economically equivalent subdivision of the Exchangeable Shares (as
                provided for in the Exchangeable Share Provisions) (an “Equivalent
                Stock Subdivision”);
                and (b) have sufficient authorized but unissued securities available
                to
                enable the Equivalent Stock
                Subdivision;

            


    

     

    
      
        
        

      

      
        2.

        
          

        

      

      
        
        

      

    

     

    
      	 	
              (b)

            	
              advise
                ExchangeCo sufficiently in advance of the declaration by Acquiror
                of any
                dividend on Acquiror Common Shares and take all such other actions
                as are
                reasonably necessary, in cooperation with ExchangeCo, to ensure that:
                (i)
                the respective declaration date, record date and payment date for
                an
                Equivalent Dividend on the Exchangeable Shares shall be the same
                as the
                declaration date, record date and payment date for the corresponding
                dividend on the Acquiror Common Shares; or (ii) the record date and
                effective date for an Equivalent Stock Subdivision shall be the same
                as
                the record date and payment date for the stock dividend on the Acquiror
                Common Shares and that such dividend on the Exchangeable Shares will
                correspond with any requirement of the principal stock exchange on
                which
                the Exchangeable Shares are listed;

            


    

     

    
      	 	
              (c)

            	
              ensure
                that the record date for any dividend declared on Acquiror Common
                Shares
                is not less than 10 Business Days after the declaration date of such
                dividend;

            


    

     

    
      	 	
              (d)

            	
              take
                all such actions and do all such things as are reasonably necessary
                or
                desirable to enable and permit ExchangeCo, in accordance with applicable
                law, to pay and otherwise perform its obligations with respect to
                the
                satisfaction of the Liquidation Amount, the Retraction Price or the
                Redemption Price in respect of each issued and outstanding Exchangeable
                Share (other than Exchangeable Shares owned by Acquiror or its Affiliates)
                upon the liquidation, dissolution or winding-up of ExchangeCo or
                any other
                distribution of the assets of ExchangeCo among its shareholders for
                the
                purpose of winding-up its affairs, the delivery of a Retraction Request
                by
                a holder of Exchangeable Shares or a redemption of Exchangeable Shares
                by
                ExchangeCo, as the case may be, including all such actions and all
                such
                things as are necessary or desirable to enable and permit ExchangeCo
                to
                cause to be delivered Acquiror Common Shares to the holders of
                Exchangeable Shares in accordance with the provisions of Articles
                5, 6 and
                7 of the Exchangeable Share Provisions, as the case may be, of the
                Exchangeable Share Provisions and cash in respect of declared and
                unpaid
                dividends;

            


    

     

    
      	 	
              (e)

            	
              take
                all such actions and do all such things as are reasonably necessary
                or
                desirable to enable and permit Callco, in accordance with applicable
                law,
                to perform its obligations arising upon the exercise by it of the
                Liquidation Call Right, the Retraction Call Right or the Redemption
                Call
                Right, including all such actions and all such things as are necessary
                or
                desirable to enable and permit Callco to cause to be delivered Acquiror
                Common Shares to the holders of Exchangeable Shares in accordance
                with the
                provisions of the Liquidation Call Right, the Retraction Call Right
                or the
                Redemption Call Right, as the case may be,
                and cash in respect of declared and unpaid dividends;
                and

            


    

     

    
      
        
        

      

      
        3.

        
          

        

      

      
        
        

      

    

     

    
      	 	
              (f)

            	
              not
                (and will ensure that Callco or any of its Affiliates does not) exercise
                its vote as a shareholder to initiate the voluntary liquidation,
                dissolution or winding-up of ExchangeCo or any other distribution
                of the
                assets of ExchangeCo among its shareholders for the purpose of winding
                up
                its affairs nor take any action or omit to take any action (and Acquiror
                will not permit Callco or any of its Affiliates to take any action
                or omit
                to take any action) that is designed to result in the liquidation,
                dissolution or winding up of ExchangeCo or any other distribution
                of the
                assets of ExchangeCo among its shareholders for the purpose of winding
                up
                its affairs.

            


    

     

    2.2 Segregation
      of Funds

     

    Acquiror
      will cause ExchangeCo to deposit a sufficient amount of funds in a separate
      account of ExchangeCo and segregate a sufficient amount of such other assets
      and
      property as is necessary to enable ExchangeCo to pay dividends when due and
      to
      pay or otherwise satisfy its respective obligations under Articles 5, 6 and
      7 of
      the Exchangeable Share Provisions or, if required, to pay the purchase price
      for
      Acquiror Common Shares as contemplated by Section 2.5, as
      applicable.

     

    2.3 Reservation
      of Acquiror Common Shares

     

    Acquiror
      hereby represents, warrants and covenants in favour of ExchangeCo and Callco
      that Acquiror has reserved for issuance and will, at all times while any
      Exchangeable Shares (other than Exchangeable Shares held by Acquiror or its
      Affiliates) are outstanding, keep available, free from pre-emptive and other
      rights, out of its authorized and unissued capital stock such number of Acquiror
      Common Shares (or other shares or securities into which Acquiror Common Shares
      may be reclassified or changed as contemplated by Section 2.7): (a) as is equal
      to the sum of: (i) the number of Exchangeable Shares issued and outstanding
      from
      time to time; and (ii) the number of Exchangeable Shares issuable upon the
      exercise of all rights to acquire Exchangeable Shares outstanding from time
      to
      time; and (b) as are now and may hereafter be required to enable and permit
      Acquiror to meet its obligations under the Voting and Exchange Trust Agreement
      and under any other security or commitment pursuant to the Arrangement with
      respect to which Acquiror may now or hereafter be required to issue Acquiror
      Common Shares, to enable and permit Callco to meet its obligations arising
      upon
      exercise by it of each of the Liquidation Call Right, the Retraction Call Right,
      the Redemption Call Right and the Change of Law Call Right (if Acquiror causes
      Callco to exercise such right) and to enable and permit ExchangeCo to meet
      its
      obligations hereunder and under the Exchangeable Share Provisions.

     

    2.4 Notification
      of Certain Events

     

    In
      order
      to assist Acquiror in compliance with its obligations hereunder and to permit
      Callco to exercise the Liquidation Call Right, the Retraction Call Right, the
      Redemption Call Right and the Change of Law Call Right (if Acquiror causes
      Callco to exercise such right), ExchangeCo will notify Acquiror and Callco
      of
      each of the following events at the times set forth below:

     

    
      	 	
              (a)

            	
              in
                the event of any determination by the Board of Directors of ExchangeCo
                to
                institute voluntary liquidation, dissolution or winding-up proceedings
                with respect to ExchangeCo or to effect any other distribution of
                the
                assets of ExchangeCo among its shareholders for the purpose of winding-up
                its affairs, at least 60 days prior to the proposed effective date
                of such
                liquidation, dissolution, winding-up or other
                distribution;

            


    

     

    
      
        
        

      

      
        4.

        
          

        

      

      
        
        

      

    

     

    
      	 	
              (b)

            	
              promptly,
                upon the earlier of receipt by ExchangeCo of notice of and ExchangeCo
                otherwise becoming aware of any threatened or instituted claim, suit,
                petition or other proceeding with respect to the involuntary liquidation,
                dissolution or winding-up of ExchangeCo or to effect any other
                distribution of the assets of ExchangeCo among its shareholders for
                the
                purpose of winding-up its affairs;

            


    

     

    
      	 	
              (c)

            	
              promptly,
                upon receipt by ExchangeCo of a Retraction
                Request;

            


    

     

    
      	 	
              (d)

            	
              promptly,
                following the date on which notice of redemption is given to holders
                of
                Exchangeable Shares, upon the determination of a Redemption Date
                in
                accordance with the Exchangeable Share
                Provisions;

            


    

     

    
      	 	
              (e)

            	
              promptly,
                upon the issuance by ExchangeCo of any Exchangeable Shares or rights
                to
                acquire Exchangeable Shares (other than the issuance of Exchangeable
                Shares and rights to acquire Exchangeable Shares in exchange for
                outstanding Target Common Shares pursuant to the Arrangement);
                and

            


    

     

    
      	 	
              (f)

            	
              promptly,
                upon receiving notice of a Change of
                Law.

            


    

     

    2.5 Delivery
      of Acquiror Common Shares to ExchangeCo and Callco

     

    In
      furtherance of its obligations under Subsections 2.1(d) and 2.1(e), upon notice
      from ExchangeCo or Callco of any event that requires ExchangeCo or Callco to
      cause to be delivered Acquiror Common Shares to any holder of Exchangeable
      Shares, Acquiror shall forthwith issue and deliver the requisite number of
      Acquiror Common Shares to be received by, and issued to or to the order of,
      the
      former holder of the surrendered Exchangeable Shares, as ExchangeCo or Callco
      shall direct. All such Acquiror Common Shares shall be duly authorized, validly
      issued and fully paid and non-assessable and shall be free and clear of any
      lien, claim or encumbrance.

     

    
      
        
        

      

      
        5.

        
          

        

      

      
        
        

      

    

     

    2.6 Qualification
      of Acquiror Common Shares

     

    Acquiror
      covenants that if any Acquiror Common Shares (or other shares or securities
      into
      which Acquiror Common Shares may be reclassified or changed as contemplated
      by
      Section 2.7) (other than Acquiror Common Shares held by the Trustee) to be
      issued and delivered hereunder (including for greater certainty, pursuant to
      the
      Exchangeable Share Provisions, or pursuant to the Change of Law Call Right,
      Exchange Right or the Automatic Exchange Rights (all as defined in the Voting
      and Exchange Trust Agreement)) require registration or qualification with,
      or
      approval of, or the filing of any document, including any prospectus or similar
      document, the taking of any proceeding with, or the obtaining of any order,
      ruling or consent from, any governmental or regulatory authority under any
      Canadian or United States federal, provincial, territorial or state securities
      or other law or regulation or pursuant to the rules and regulations of any
      securities or other regulatory authority, or the fulfillment of any other United
      States or Canadian legal requirement (collectively, the “Applicable
      Laws”)
      before
      such shares (or other shares or securities into which Acquiror Common Shares
      may
      be reclassified or changed as contemplated by Section 2.7) may be issued and
      delivered by Acquiror at the direction of ExchangeCo or Callco, if applicable,
      to the holder of surrendered Exchangeable Shares or in order that such shares
      (or other shares or securities into which Acquiror Common Shares may be
      reclassified or changed as contemplated by Section 2.7) may be freely traded
      thereafter (other than any restrictions of general application on transfer
      by
      reason of a holder being a “control person” of Acquiror for purposes of Canadian
      provincial securities law or an “affiliate” of Acquiror for purposes of United
      States federal or state securities law), Acquiror will use its reasonable best
      efforts and in good faith expeditiously take all such actions and do all such
      things as are necessary or desirable and within its power to cause such Acquiror
      Common Shares (or other shares or securities into which Acquiror Common Shares
      may be reclassified or changed as contemplated by Section 2.7) to be and remain
      duly registered, qualified or approved under United States and/or Canadian
      law,
      as the case may be, to the extent expressly provided in the Arrangement
      Agreement. Acquiror will use its reasonable best efforts and in good faith
      expeditiously take all such actions and do all such things as are reasonably
      necessary or desirable to cause all Acquiror Common Shares (or other shares
      or
      securities into which Acquiror Common Shares may be reclassified or changed
      as
      contemplated by Section 2.7) (other than Acquiror Common Shares held by the
      Trustee) to be delivered hereunder to be listed, quoted or posted for trading
      on
      all stock exchanges and quotation systems on which outstanding Acquiror Common
      Shares (or other shares or securities into which Acquiror Common Shares may
      be
      reclassified or changed as contemplated by Section 2.7) are listed and are
      quoted or posted for trading at such time.

     

    2.7 Economic
      Equivalence

     

    So
      long
      as any Exchangeable Shares not owned by Acquiror or its Affiliates are
      outstanding:

     

    
      	 	
              (a)

            	
              Acquiror
                will not, without prior approval of ExchangeCo and the prior approval
                of
                the holders of the Exchangeable Shares given in accordance with Section
                10.2 of the Exchangeable Share
                Provisions:

            


    

     

    
      	 	
              (i)

            	
              issue
                or distribute Acquiror Common Shares (or securities exchangeable
                for or
                convertible into or carrying rights to acquire Acquiror Common Shares)
                to
                the holders of all or substantially all of the then outstanding Acquiror
                Common Shares by way of stock dividend or other distribution, other
                than
                an issue of Acquiror Common Shares (or securities exchangeable for
                or
                convertible into or carrying rights to acquire Acquiror Common Shares)
                to
                holders of Acquiror Common Shares who: (A) exercise an option to
                receive
                dividends in Acquiror Common Shares (or securities exchangeable for
                or
                convertible into or carrying rights to acquire Acquiror Common Shares)
                in
                lieu of receiving cash dividends; or (B) pursuant
                to any dividend reinvestment plan or scrip dividend;
                or

            


    

     

    
      	 	
              (ii)

            	
              issue
                or distribute rights, options or warrants to the holders of all or
                substantially all of the then outstanding Acquiror Common Shares
                entitling
                them to subscribe for or to purchase Acquiror Common Shares (or securities
                exchangeable for or convertible into or carrying rights to acquire
                Acquiror Common Shares); or

            


    

     

    
      
        
        

      

      
        6.

        
          

        

      

      
        
        

      

    

     

    
      	 	
              (iii)

            	
              issue
                or distribute to the holders of all or substantially all of the then
                outstanding Acquiror Common Shares: (A) shares or securities of Acquiror
                of any class other than Acquiror Common Shares (other than shares
                convertible into or exchangeable for or carrying rights to acquire
                Acquiror Common Shares); (B) rights, options or warrants other than
                those
                referred to in Subsection 2.7(a)(ii); (C) evidences
                of indebtedness of Acquiror; or (D) assets
                of Acquiror, 

            


    

     

    unless
      the economic equivalent on a per share basis of such rights, options, warrants,
      securities, shares, evidences of indebtedness or other assets is issued or
      distributed simultaneously to holders of the Exchangeable Shares; provided
      that,
      for greater certainty, the above restrictions shall not apply to any securities
      issued or distributed by Acquiror in order to give effect to and to consummate
      the transactions contemplated by, and in accordance with, the Arrangement
      Agreement.

     

    
      	 	
              (b)

            	
              Acquiror
                will not without the prior approval of ExchangeCo and the prior approval
                of the holders of the Exchangeable Shares given in accordance with
                Section
                10.2 of the Exchangeable Share
                Provisions:

            


    

     

    
      	 	
              (i)

            	
              subdivide,
                redivide or change the then outstanding Acquiror Common Shares into
                a
                greater number of Acquiror Common Shares;
                or

            


    

     

    
      	 	
              (ii)

            	
              reduce,
                combine, consolidate or change the then outstanding Acquiror Common
                Shares
                into a lesser number of Acquiror Common Shares;
                or

            


    

     

    
      	 	
              (iii)

            	
              reclassify
                or otherwise change Acquiror Common Shares or effect an amalgamation,
                merger, reorganization or other transaction affecting the Acquiror
                Common
                Shares,

            


    

     

    unless
      the same or an economically equivalent change shall simultaneously be made
      to,
      or in the rights of the holders of, the Exchangeable Shares; provided that,
      for
      greater certainty, the above restrictions shall not apply to any securities
      issued or distributed by Acquiror in order to give effect to and to consummate
      the transactions contemplated by, and in accordance with, the Arrangement
      Agreement.

     

    
      	 	
              (c)

            	
              Acquiror
                will ensure that the record date for any event referred to in Subsections
                2.7(a) or 2.7(b), or (if no record date is applicable for such event)
                the
                effective date for any such event, is not less than five Business
                Days
                after the date on which such event is declared or announced by Acquiror
                (with contemporaneous notification thereof by Acquiror to
                ExchangeCo).

            


    

     

    
      	 	
              (d)

            	
              The
                Board of Directors of ExchangeCo shall determine, in good faith and
                in its
                sole discretion, economic equivalence for the purposes of any event
                referred to in Subsections 2.7(a) or 2.7(b) and each such determination
                shall be conclusive and binding on Acquiror and the holders of the
                Exchangeable Shares. In making each such determination, the following
                factors shall, without excluding other factors determined by the
                Board of
                Directors of ExchangeCo to be relevant, be considered by the Board
                of
                Directors of ExchangeCo:

            


    

     

    
      
        
        

      

      
        7.

        
          

        

      

      
        
        

      

    

     

    
      	 	
              (i)

            	
              in
                the case of any stock dividend or other distribution payable in Acquiror
                Common Shares, the number of such shares issued in proportion to
                the
                number of Acquiror Common Shares previously
                outstanding;

            


    

     

    
      	 	
              (ii)

            	
              in
                the case of the issuance or distribution of any rights, options or
                warrants to subscribe for or purchase Acquiror Common Shares (or
                securities exchangeable for or convertible into or carrying rights
                to
                acquire Acquiror Common Shares), the relationship between the exercise
                price of each such right, option or warrant and the Current Market
                Price,
                the volatility of the Acquiror Common Shares and the term of such
                instrument;

            


    

     

    
      	 	
              (iii)

            	
              in
                the case of the issuance or distribution of any other form of property
                (including any shares or securities of Acquiror of any class other
                than
                Acquiror Common Shares, any rights, options or warrants other than
                those
                referred to in Subsection 2.7(d)(ii), any evidences of indebtedness
                of
                Acquiror or any assets of Acquiror), the relationship between the
                fair
                market value (as determined by the Board of Directors of ExchangeCo
                in the
                manner above contemplated) of such property to be issued or distributed
                with respect to each outstanding Acquiror Common Share and the Current
                Market Price;

            


    

     

    
      	 	
              (iv)

            	
              in
                the case of any subdivision, redivision or change of the then outstanding
                Acquiror Common Shares into a greater number of Acquiror Common Shares
                or
                the reduction, combination, consolidation or change of the then
                outstanding Acquiror Common Shares into a lesser number of Acquiror
                Common
                Shares or any amalgamation, merger, reorganization or other transaction
                affecting Acquiror Common Shares, the effect thereof upon the then
                outstanding Acquiror Common Shares;
                and

            


    

     

    
      	 	
              (v)

            	
              in
                all such cases, the general taxation consequences of the relevant
                event to
                holders of Exchangeable Shares to the extent that such consequences
                may
                differ from the taxation consequences to holders of Acquiror Common
                Shares
                as a result of differences between taxation laws of Canada and the
                United
                States (except for any differing consequences arising as a result
                of
                differing marginal taxation rates and without regard to the individual
                circumstances of holders of Exchangeable
                Shares).

            


    

     

    
      	 	
              (e)

            	
              ExchangeCo
                agrees that, to the extent required, upon due notice from Acquiror,
                ExchangeCo will use its best efforts to take or cause to be taken
                such
                steps as may be necessary for the purposes of ensuring that appropriate
                dividends are paid or other distributions are made by ExchangeCo,
                or
                subdivisions, redivisions or changes are made to the Exchangeable
                Shares,
                in order to implement the required economic equivalent with respect
                to the
                Acquiror Common Shares and Exchangeable Shares as provided for in
                this
                Section 2.7.

            


    

     

    
      
        
        

      

      
        8.

        
          

        

      

      
        
        

      

    

     

    2.8 Tender
      Offers

     

    For
      so
      long as Exchangeable Shares remain outstanding (not including Exchangeable
      Shares held by Acquiror and its Affiliates), in the event that a tender offer,
      share exchange offer, issuer bid, take-over bid or similar transaction with
      respect to Acquiror Common Shares (an “Offer”)
      is
      proposed by Acquiror or is proposed to Acquiror or its shareholders and is
      recommended by the Board of Directors of Acquiror, or is otherwise effected
      or
      to be effected with the consent or approval of the Board of Directors of
      Acquiror, and the Exchangeable Shares are not redeemed by ExchangeCo or
      purchased by Callco pursuant to the Redemption Call Right, Acquiror will use
      its
      reasonable best efforts expeditiously and in good faith to take all such actions
      and do all such things as are necessary or desirable to enable and permit
      holders of Exchangeable Shares (other than Acquiror and its Affiliates) to
      participate in such offer to the same extent and on an economically equivalent
      basis as the holders of Acquiror Common Shares, without discrimination. Without
      limiting the generality of the foregoing, Acquiror will use its reasonable
      best
      efforts expeditiously and in good faith to ensure that holders of Exchangeable
      Shares may participate in each such offer without being required to retract
      Exchangeable Shares as against ExchangeCo (or, if so required, to ensure that
      any such retraction, shall be effective only upon, and shall be conditional
      upon, the closing of such Offer and only to the extent necessary to tender
      or
      deposit to the Offer). Nothing herein shall affect the rights of ExchangeCo
      to
      redeem (or Callco to purchase pursuant to the Redemption Call Right)
      Exchangeable Shares, as applicable, in the event of an Acquiror Control
      Transaction.

     

    2.9 Ownership
      of Outstanding Shares

     

    Without
      the prior approval of ExchangeCo and the prior approval of the holders of the
      Exchangeable Shares given in accordance with Section 10.2 of the Exchangeable
      Share Provisions, Acquiror covenants and agrees in favour of ExchangeCo that,
      as
      long as any outstanding Exchangeable Shares are owned by any Person other than
      Acquiror or any of its Affiliates, Acquiror will be and remain the direct or
      indirect beneficial owner of all issued and outstanding voting shares in the
      capital of ExchangeCo and Callco. Notwithstanding the foregoing, Acquiror shall
      not be in violation of this Section 2.9 if any person or group of persons acting
      jointly or in concert acquires all or substantially all of the assets of
      Acquiror or the Acquiror Common Shares pursuant to any merger of Acquiror
      pursuant to which Acquiror was not the surviving corporation.

     

    2.10 Acquiror
      and Affiliates Not to Vote Exchangeable Shares

     

    Acquiror
      and Callco each covenants and agrees that it will not, and will cause its
      Affiliates not to, exercise any voting rights which may be exercisable by
      holders of Exchangeable Shares from time to time pursuant to the Exchangeable
      Share Provisions or pursuant to the provisions of the ABCA (or any successor
      or
      other corporate statute by which ExchangeCo may in the future be governed)
      with
      respect to any Exchangeable Shares held by it or by its Affiliates in respect
      of
      any matter considered at any meeting of holders of Exchangeable
      Shares.

     

    
      
        
        

      

      
        9.

        
          

        

      

      
        
        

      

    

     

    2.11 Rule
      10b-18 Purchases

     

    For
      greater certainty, nothing contained in this Agreement, including the
      obligations of Acquiror contained in Section 2.8, shall limit the ability of
      Acquiror or ExchangeCo to make a “Rule 10b-18 purchase” of Acquiror Common
      Shares pursuant to Rule 10b-18 of the United States Securities
      Exchange Act of 1934,
      as
      amended, or any successor rule.

     

    2.12 Stock
      Exchange Listing

     

    Acquiror
      covenants and agrees in favour of ExchangeCo that, as long as any outstanding
      Exchangeable Shares are owned by any Person other than Acquiror or any of its
      Affiliates, Acquiror will use its reasonable best efforts to maintain a listing
      for such Exchangeable Shares on a Canadian stock exchange which is a designated
      stock exchange within the meaning of the Income
      Tax Act (Canada)
      (the “Tax
      Act”)
      and to
      ensure that ExchangeCo remains a “public corporation” within the meaning of the
      Tax Act and maintains a “substantial Canadian presence” within the meaning of
      the Tax Act as in effect on the date of this Agreement.

     

    ARTICLE
      3

    ACQUIROR
      SUCCESSORS

     

    3.1 Certain
      Requirements in Respect of Combination, etc.

     

    Neither
      Acquiror nor Callco shall consummate any transaction (whether by way of
      reconstruction, reorganization, consolidation, merger, transfer, sale, lease
      or
      otherwise) whereby all or substantially all of its undertaking, property and
      assets would become the property of any other Person or, in the case of a
      merger, of the continuing corporation resulting therefrom unless, but may do
      so
      if:

     

    
      	 	
              (a)

            	
              such
                other Person or continuing corporation (the “Acquiror
                Successor”)
                by operation of law, becomes, without more, bound by the terms and
                provisions of this Agreement or, if not so bound, executes, prior
                to or
                contemporaneously with the consummation of such transaction, an agreement
                supplemental hereto and such other instruments (if any) as are reasonably
                necessary or advisable to evidence the assumption by the Acquiror
                Successor of liability for all moneys payable and property deliverable
                hereunder and the covenant of such Acquiror Successor to pay and
                deliver
                or cause to be delivered the same and its agreement to observe and
                perform
                all the covenants and obligations of Acquiror or Callco, as the case
                may
                be, under this Agreement;

            


    

     

    
      	 	
              (b)

            	
              in
                the event that the Acquiror Common Shares are reclassified or otherwise
                changed as part of such transaction, the same or an economically
                equivalent change is simultaneously made to, or in the rights of
                the
                holders of, the Exchangeable Shares; and


            


    

     

    
      	 	
              (c)

            	
              such
                transaction shall be upon such terms and conditions as substantially
                to
                preserve and not to impair in any material respect any of the rights,
                duties, powers and authorities of the other parties hereunder or
                the
                holders of Exchangeable Shares.

            


    

     

    
      
        
        

      

      
        10.

        
          

        

      

      
        
        

      

    

     

    3.2 Vesting
      of Powers in Successor

     

    Whenever
      the conditions of Section 3.1 have been duly observed and performed, the
      parties, if required by Section 3.1, shall execute and deliver the supplemental
      agreement provided for in Subsection 3.1(a) and thereupon the Acquiror Successor
      shall possess and from time to time may exercise each and every right and power
      of Acquiror or Callco, as the case may be, under this Agreement in the name
      of
      Acquiror or otherwise and any act or proceeding by any provision of this
      Agreement required to be done or performed by the Board of Directors of Acquiror
      or any officers of Acquiror may be done and performed with like force and effect
      by the directors or officers of such Acquiror Successor.

     

    3.3 Wholly-Owned
      Subsidiaries

     

    Nothing
      herein shall be construed as preventing the amalgamation or merger of any
      wholly-owned direct or indirect subsidiary of Acquiror (other than ExchangeCo
      or
      Callco) with or into Acquiror or the winding-up, liquidation or dissolution
      of
      any wholly-owned subsidiary of Acquiror provided that all of the assets of
      such
      subsidiary are transferred to Acquiror or another wholly-owned direct or
      indirect subsidiary of Acquiror and any such transactions are expressly
      permitted by this Article 3.

     

    3.4 Successorship
      Transaction

     

    Notwithstanding
      the foregoing provisions of Article 3, in the event of an Acquiror Control
      Transaction:

     

    
      	 	
              (a)

            	
              in
                which Acquiror merges or amalgamates with, or in which all or
                substantially all of the then outstanding Acquiror Common Shares
                are
                acquired by, one or more other corporations to which Acquiror is,
                immediately before such merger, amalgamation or acquisition, “related’’
                within the meaning of the Tax Act (otherwise than by virtue of a
                right
                referred to in paragraph 251(5)(b)
                thereof);

            


    

     

    
      	 	
              (b)

            	
              which
                does not result in an acceleration of the Redemption Date in accordance
                with paragraph (b) of that definition; and


            


    

     

    
      	 	
              (c)

            	
              in
                which all or substantially all of the then outstanding Acquiror Common
                Shares are converted into or exchanged for shares or rights to receive
                such shares (the “Other
                Shares”)
                or another corporation (the “Other
                Corporation”)
                that, immediately after such Acquiror Control Transaction, owns or
                controls, directly or indirectly,
                Acquiror,

            


    

     

    then
      all
      references herein to “Acquiror’’ shall thereafter be and be deemed to be
      references to “Other Corporation’’ and all references herein to “Acquiror Common
      Shares” shall thereafter be and be deemed to be references to “Other Shares’’
(with appropriate adjustments, if any, as are required to result in a holder
      of
      Exchangeable Shares on the exchange, redemption or retraction of such shares
      pursuant to the Exchangeable Share Provisions or Article 8 of the Plan of
      Arrangement or exchange of such shares pursuant to the Voting and Exchange
      Trust
      Agreement immediately subsequent to the Acquiror Control Transaction being
      entitled to receive that number of Other Shares equal to the number of Other
      Shares such holder of Exchangeable Shares would have received if the exchange,
      redemption or retraction of such shares pursuant to the Exchangeable Share
      Provisions or Article 8 of the Plan of Arrangement, or exchange of such shares
      pursuant to the Voting and Exchange Trust Agreement had occurred immediately
      prior to the Acquiror Control Transaction and the Acquiror Control Transaction
      was completed) without any need to amend the terms and conditions of the
      Exchangeable Shares and without any further action required.

     

    
      
        
        

      

      
        11.

        
          

        

      

      
        
        

      

    

     

    ARTICLE
      4

    GENERAL

     

    4.1 Term

     

    This
      Agreement shall come into force and be effective as of the date hereof and
      shall
      terminate and be of no further force and effect at such time as no Exchangeable
      Shares (or securities or rights convertible into or exchangeable for or carrying
      rights to acquire Exchangeable Shares) are held by any Person other than
      Acquiror and any of its Affiliates.

     

    4.2 Changes
      in Capital of Acquiror and ExchangeCo

     

    At
      all
      times after the occurrence of any event contemplated pursuant to Sections 2.7
      and 2.8 hereof or otherwise, as a result of which either Acquiror Common Shares
      or the Exchangeable Shares or both are in any way changed, this Agreement shall
      forthwith be deemed amended and modified as necessary in order that it shall
      apply with full force and effect, mutatis
      mutandis,
      to all
      new securities into which Acquiror Common Shares or the Exchangeable Shares
      or
      both are so changed and the parties hereto shall execute and deliver an
      agreement in writing giving effect to and evidencing such necessary amendments
      and modifications.

     

    4.3 Notices
      to Parties

     

    All
      notices and other communications hereunder shall be in writing and shall be
      deemed given when delivered personally, telecopied (which is confirmed) or
      dispatched (postage prepaid) to a nationally recognized overnight courier
      service with overnight delivery instructions, in each case addressed to the
      particular party at:

     

    
      	 	
              (a)

            	
              If
                to Acquiror, at:

            


    

     

    Gran
      Tierra Energy Inc.

    #300,
      611 – 10th
      Avenue
      S.W.

    Calgary,
      Alberta T2R 0B2

    Attention:               
      Dana
      Coffield, Ph. D., President & Chief Executive Officer

    Facsimile
      Number:  (403)
      265-3242

     

    
      
        
        

      

      
        12.

        
          

        

      

      
        
        

      

    

     

    
      	 	
              (b)

            	
              If
                to ExchangeCo, at:

            


    

     

    Gran
      Tierra Exchangeco Inc.

    #300,
      611 – 10th
      Avenue
      S.W.

    Calgary,
      Alberta T2R 0B2

    Attention:               
      Dana
      Coffield, Ph. D., President & Chief Executive Officer

    Facsimile
      Number:  (403)
      265-3242

     

    
      	 	
              (c)

            	
              If
                to Callco, at:

            


    

     

    Gran
      Tierra Callco ULC

    #300,
      611 – 10th
      Avenue
      S.W.

    Calgary,
      Alberta T2R 0B2

    Attention:               
      Dana
      Coffield, Ph. D., President & Chief Executive Officer

    Facsimile
      Number:  (403)
      265-3242

     

    or
      at
      such other address of which any party may, from time to time, advise the other
      parties by notice in writing given in accordance with the
      foregoing.

     

    4.4 Assignment

     

    No
      party
      hereto may assign this Agreement or any of its rights, interests or obligations
      under this Agreement or the Arrangement (whether by operation of law or
      otherwise) except that ExchangeCo may assign in its sole discretion, any or
      all
      of its rights, interests and obligations hereunder to any wholly-owned
      subsidiary of Acquiror.

     

    4.5 Binding
      Effect

     

    Subject
      to Section 4.4, this Agreement and the Arrangement shall be binding upon, enure
      to the benefit of and be enforceable by the parties hereto and their respective
      successors and assigns.

     

    4.6 Amendments,
      Modifications

     

    Subject
      to Sections 4.2, 4.7 and 4.11, this Agreement may not be amended or modified
      except by an agreement in writing executed by ExchangeCo, Callco and Acquiror
      and approved by the holders of the Exchangeable Shares in accordance with
      Section 10.2 of the Exchangeable Share Provisions.

     

    4.7 Ministerial
      Amendments

     

    Notwithstanding
      the provisions of Section 4.6, the parties to this Agreement may in writing
      at
      any time and from time to time, without the approval of the holders of the
      Exchangeable Shares, amend or modify this Agreement for the purposes
      of:

     

    
      	 	
              (a)

            	
              adding
                to the covenants of any or all parties provided that the board of
                directors of each of ExchangeCo, Callco and Acquiror shall be of
                the good
                faith opinion that such additions will not be prejudicial to the
                rights or
                interests of the holders of the Exchangeable
                Shares;

            


    

     

    
      
        
        

      

      
        13.

        
          

        

      

      
        
        

      

    

     

    
      	 	
              (b)

            	
              making
                such amendments or modifications not inconsistent with this Agreement
                as
                may be necessary or desirable with respect to matters or questions
                which,
                in the good faith opinion of the board of directors of each of ExchangeCo,
                Callco and Acquiror, it may be expedient to make, provided that each
                such
                board of directors shall be of the good faith opinion that such amendments
                or modifications will not be prejudicial to the rights or interests
                of the
                holders of the Exchangeable Shares;
                or

            


    

     

    
      	 	
              (c)

            	
              making
                such changes or corrections which, on the advice of counsel to ExchangeCo,
                Callco and Acquiror, are required for the purpose of curing or correcting
                any ambiguity or defect or inconsistent provision or clerical omission
                or
                mistake or manifest error, provided that the board of directors of
                each of
                ExchangeCo, Callco and Acquiror shall be of the good faith opinion
                that
                such changes or corrections will not be prejudicial to the rights
                or
                interests of the holders of the Exchangeable
                Shares.

            


    

     

    4.8 Meeting
      to Consider Amendments

     

    ExchangeCo,
      at the request of Acquiror, shall call a meeting or meetings of the holders
      of
      the Exchangeable Shares for the purpose of considering any proposed amendment
      or
      modification requiring approval pursuant to Section 4.6. Any such meeting or
      meetings shall be called and held in accordance with the bylaws of ExchangeCo,
      the Exchangeable Share Provisions and all applicable laws.

     

    4.9 Amendments
      Only in Writing

     

    No
      amendment to or modification or waiver of any of the provisions of this
      Agreement otherwise permitted hereunder shall be effective unless made in
      writing and signed by all of the parties hereto.

     

    4.10 Governing
      Laws; Consent to Jurisdiction

     

    This
      Agreement shall be governed by and construed in accordance with the laws of
      the
      Province of Alberta and the laws of Canada applicable therein and shall be
      treated in all respects as an Alberta contract. Each party hereby irrevocably
      attorns to the jurisdiction of the courts of the Province of Alberta in respect
      of all matters arising under or in relation to this Agreement.

     

    4.11 Severability

     

    If
      any
      term or other provision of this Agreement is invalid, illegal or incapable
      of
      being enforced by any rule of law or public policy, all other conditions and
      provisions of this Agreement shall nevertheless remain in full force and effect
      so long as the economic or legal substance of the transactions contemplated
      hereby is not affected in any manner materially adverse to any party. Upon
      such
      determination that any term or other provision is invalid, illegal or incapable
      of being enforced, the parties hereto shall negotiate in good faith to modify
      this Agreement so as to effect the original intent of the parties as closely
      as
      possible in an acceptable manner to the end that transactions contemplated
      hereby are fulfilled to the extent possible.

     

    4.12 Counterparts

     

    This
      Agreement may be executed in counterparts, each of which shall be deemed to
      be
      an original but all of which together shall constitute one and the same
      instrument.

     

    
      
        
        

      

      
        14.

        
          

        

      

      
        
        

      

    

     

    IN
      WITNESS WHEREOF,
      the
      parties hereto have caused this Agreement to be duly executed as of the date
      first above written.

     

    
      	
              GRAN
                TIERRA ENERGY INC.

            
	  
	 
              
	
              By:
                

            	
              /s/
                Dana Coffield

            
	
              Name:

            	
              Dana
                Coffield, Ph. D.

            
	
              Title:

            	
              President
                and Chief Executive Officer

            
	 
	 
	
              GRAN
                TIERRA EXCHANGECO INC.

            
	 
	 
	
              By:
                

            	
              /s/
                Dana Coffield

            
	
              Name:

            	
              Dana
                Coffield, Ph. D.

            
	
              Title:

            	
              President
                and Chief Executive Officer

            
	 
	 
	
              GRAN
                TIERRA CALLCO ULC

            
	 
	 
	
              By:
                

            	
              /s/
                Dana Coffield

            
	
              Name:

            	
              Dana
                Coffield, Ph. D.

            
	
              Title:

            	
              President
                and Chief Executive Officer

            


    

    


    
      
        
        

      

      
        15.