5 January 2006

Gran Tierra Announces Completion of Argentina Oil Drilling Operations

CALGARY, Alberta, Jan. 5 /CNW/ – Gran Tierra Energy, Inc. (OTC Bulletin Board: GTRE.OB) today announced the successful completion of the drilling of the Ramon Lista-1001 well located approximately 10 kilometers north-west of the producing Palmar Largo Field in the Noroeste Basin of Argentina.

Gran Tierra acquired a 14% interest in the Palmar Largo Joint Venture in September, 2005. Gran Tierra’s share of production from the Palmar Largo Joint Venture averaged approximately 325 barrels per day (net before royalties) over the fourth quarter of 2005. Based upon initial review of well logs, initial production from the Ramon Lista-1001 well is estimated to be in the range of 500 barrels per day (gross before royalties) which would represent an additional 70 barrels per day net to Gran Tierra’s interest.

Ramon Lista-1001 reached a final measured depth of 4,301 meters on December 25, 2005. Its primary objective was the Palmar Largo Formation, the major producing horizon of the Palmar Largo Field. An upper member of the Yacoraite Formation, the Puesto Guardian, was the secondary objective. Initial interpretation of logs indicates net hydrocarbon pay of approximately 27 meters and 15 meters for the two reservoirs respectively. A 7 inch liner has been run. The drilling rig will be moved off site and a wireline unit will be used to perforate the reservoirs in the coming week, with first production following tie-in to nearby facilities currently projected to begin within one month.

Dana Coffield, the Company’s President and CEO, stated, “We are very pleased with the initial prognosis for this well. The potential for near-term addition of new reserves and production to our established production base is an important element of our basic strategy to build a mixed portfolio of exploration and production opportunities to create substantial value for our shareholders.”

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 currently holds interests in producing and non-producing properties in Argentina and is pursuing a growth strategy that focuses on establishing a portfolio of producing properties, and development and exploration opportunities, by selective acquisitions, to provide a base for future growth. Additional information concerning Gran Tierra is available at http://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, failing to discover reserves that may be extracted on a commercially viable basis, inaccurately estimating oil and gas reserves, intense competition, environmental risks 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.