CALGARY, Alberta, April 26, 2006 Gran Tierra Energy, Inc. (OTC Bulletin Board: GTRE.OB) today announced that Dana Coffield, President and Chief Executive Officer of the company, will present a profile of Gran Tierra at the Stock Day Resources Conference in Frankfurt, Germany on May 24 and 25, 2006. This important resource sector conference is hosted by Value Relations GmbH, for the benefit of the international investment community. The company will be posting a copy of the presentation on its website at www.grantierra.com at that time.

Gran Tierra continues to advance its diligence and documentation for all acquisition initiatives announced earlier in the year. The acquisition of Argosy Energy International for a total consideration of $42 million, consisting of $37.5 million in cash, $3.5 million in common shares of Gran Tierra and certain overriding and net profit interests in the acquired assets valued at $1 million, is scheduled to close on or prior to May 31, 2006. According to the terms of the February 15, 2006 agreement for the acquisition of certain assets of Compa~n'ia General de Combustibles S.A. (CGC) in Argentina, up to $5.0 million of the total purchase price of $37.8 million is payable, at the option of CGC, in stock or cash. CGC has elected to receive the full consideration in cash. Closing of the CGC acquisition has been extended to June 30, 2006 or earlier to provide sufficient time for required authorizations. Closing of the company's $0.95 million acquisition and farm-in agreement with Golden Oil Corporation in Argentina has also been re-scheduled to May 31, 2006 or earlier to coincide with the Argosy closing. According to terms of the Golden Oil transaction, Gran Tierra would fund up to $2.7 million of the cost of a planned sidetrack well in the El Vinalar area. All pending acquisitions remain subject to customary closing conditions.

The following tables summarize the estimated 2006 production and reserve impacts of the respective acquisitions subsequent to the completion of the acquisitions. All volume data are expressed on a before and after royalty basis and assume a 6:1 conversion for natural gas to oil. Management's estimates of production are based on current production, budgets and available reserve information. Reserve estimates are as of December 31, 2005.

Post Acquisition Pro Forma Production Summary

Post Acquisition Pro Forma Reserve Summary

Total acreage for Gran Tierra would increase to 1,691,800 net acres upon closing of all acquisitions.

Based on the company's current assessment of drilling opportunities, exploration leads and prospects, estimated resource potential across all properties is approximately 56 million barrels of oil equivalent, after adjustments for risk in the company's reasonable estimation (after royalty, 6:1 conversion). A total of 19 exploration prospects and 36 leads have currently been identified for these properties.

Planned work programs for the combined acquisitions for 2006/early-2007 include the drilling of nine wells (gross) in addition to well workovers and facility upgrades, contributing to a capital expenditure budget of approximately $25 million for Gran Tierra for the period. Approximately $16 million of the total is drilling related. If successful, the company estimates that planned activities would add approximately 1.0 thousand barrels of oil equivalent per day of production to Gran Tierra, adjusted for risk (after royalty, 6:1 conversion).

Post Acquisition Pro Forma Financial Impact

The estimated financial impact of the announced acquisitions is summarized below, on the basis that all acquisitions are completed. As all acquisitions would occur partially through the year, actual production and financial results for 2006 will be an average of pre and post-closing results. The following figures are based on a WTI oil price of $60/Bbl and contracted natural gas prices and are management's estimates according to current and anticipated production, budgets and fiscal conditions. Natural gas is converted to oil at a 6:1 ratio.

Production 3,116 Boe/day
Net Revenue
Oil $40.29/Bbl
Gas $1.63/Mcf
Total $28.28/Boe
Lease Operating Expense $6.19 - $7.56/Boe
G&A $4.06 - $4.97/Boe
EBITDA $15.75 - $18.03/Boe

Dana Coffield, President and Chief Executive Officer of Gran Tierra, stated, "We are moving purposefully to bring our acquisitions to closure while we continue to evaluate new business opportunities. Staffing initiatives in Buenos Aires have now positioned Gran Tierra to take on a role as an operator in the country, in addition to accelerating the pace of new venture activity in the country. We continue to pursue opportunities for growth in Colombia, to complement our entry strategy. Our expanding profile in South America is opening new opportunities for us in the region, and we are working to capitalize on this. It is a busy and exciting time for our company, as we prepare the foundation for a new level of growth for our company."

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 strategy that focuses on establishing a portfolio of producing properties, and development and exploration opportunities, through selective acquisitions, to provide a base for future growth.

Gran Tierra initiated three acquisitions in the first quarter of 2006: one significant acquisition of producing properties in Argentina to expand and broaden its activities in the Noroeste region of the country; one smaller "tuck-in" acquisition, also in the Noroeste Basin, providing additional production and drilling opportunities; and this third acquisition of Argosy International, which provides a sizeable entry for the company into Colombia.

Gran Tierra is continuing to assess growth opportunities and expects to continue its strategy of moving aggressively and sensibly to build a diverse, self-sustaining and active international oil and gas company. Additional information concerning Gran Tierra is available at http://www.grantierra.com. Investor inquiries may be directed to [email protected] 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.