7 November 2006

Gran Tierra Acquires Properties in Argentina; Expands Prospective Land and Operating Presence in the Noroeste Basin

CALGARY, Alberta, November 7, 2006 – Gran Tierra Energy Inc. (OTC Bulletin Board: GTRE.OB) – On November 2, 2006 Gran Tierra completed the acquisition of interests in four properties from Compania General de Combustibles S.A. (CGC) for a total consideration of $2.1 million. The assets acquired include a 93.18% participation in the Valle Morado Block, a 100% interest in the Santa Victoria Block and the remaining 50% interests in the Nacatimbay and Ipaguazu Blocks (in which the Company currently holds 50% interests). These properties add approximately 1.1 million gross acres to the Company’s current land base and exploration/development portfolio in the Noroeste Basin in northern Argentina. Gran Tierra will be the operator of all four properties.

The Company’s offer to purchase CGC’s interests in eight properties in Argentina was initially made on February 22, 2006. Completion of the acquisitions has since been subject to various authorizations within Argentina including local court approvals, the potential exercise of rights of first refusal and certain third-party consents.

Court approval has since been obtained, allowing the Company to complete the acquisition of the interests in the four properties. Gran Tierra is considering its options to acquire the interests in the remaining four properties, which interests remain subject to rights of first refusal among joint venture partners and other third party consents.

Dana Coffield, President and Chief Executive Officer of Gran Tierra, stated, “When we made our initial offer to CGC, our Company had a small, newly-acquired base of operations in Argentina. We were targeting entry opportunities in Colombia and Peru. We were operating in a buoyant oil and gas market, and our growth ambitions were dependent on financing. Nine months later we are in a very different position. We have established ourselves in three countries. We are moving into a second stage of growth, focused on drilling. We have cash in the bank and a portfolio of opportunities. We are in a position to high-grade our investment decisions moving forward, taking risks, uncertainty, upside and shareholder value into account. It is a good position to be in at this stage of our growth and at this time in the market.”

About Gran Tierra Energy Inc.
Gran Tierra Energy, Inc. is an international oil and gas exploration and production company, headquartered in Calgary, Canada, incorporated and traded in the United States and operating in South America. The Company now holds interests in producing and prospective properties in Argentina, Colombia and Peru. To date, the Company has pursued a strategy that focuses on establishing a portfolio of producing properties, development and exploration opportunities, through selective acquisitions, to provide a base for future growth. Additional information concerning Gran Tierra is available at www.grantierra.com. Investor inquiries may be directed to info@grantierra.com or 1-800-916-GTRE (4873).

Forward Looking Statements
This press release contains ‘forward-looking statements’ within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, including without limitation those statements regarding the Company’s ability to exploit oil and gas exploration opportunities. These statements are expressed in good faith and based upon a reasonable basis when made, but there can be no assurance that these expectations will be achieved or accomplished. Although the forward-looking statements in this release reflect the good faith judgment of management, forward-looking statements are inherently subject to known and unknown risks and uncertainties that may cause actual results to be materially different from those discussed in these forward-looking statements including, but not limited to, our ability to complete each of the potential acquisitions discussed above on anticipated terms and in a timely manner, including the completion of financing relating thereto on satisfactory terms, our ability to discover reserves that may be extracted on a commercially viable basis, difficulties inherent in estimating oil and gas reserves, intense competition in the oil and gas industry, environmental risks, regulatory changes and general economic conditions including the price of oil and gas. Readers are urged not to place undue reliance on these forward-looking statements, which speak only as of the date of this release. We assume no obligation to update any forward-looking statements in order to reflect any event or circumstance that may arise after the date of this release, other than as may be required by applicable law or regulation. Readers are urged to carefully review and consider the various disclosures made by us in the our reports filed with the Securities and Exchange Commission, including those risks set forth in the Company’s Current Report on Form 8-K filed on November 10, 2005, which attempt to advise interested parties of the risks and factors that may affect our business, financial condition, results of operation and cash flows. If one or more of these risks or uncertainties materialize, or if the underlying assumptions prove incorrect, our actual results may vary materially from those expected or projected. We undertake no obligation to update these forward looking statements.