7 April 2008

Gran Tierra Energy to Trade on The American Stock Exchange

Trading to Begin April 8, 2008, Under the Symbol “GTE”

CALGARY, Canada, April 7, 2008 – Gran Tierra Energy Inc. (TSX: GTE; OTC BB: GTRE), a company focused on oil exploration and production in South America, today announced that its common stock listing application has been approved by the American Stock Exchange (the “AMEX”). This approval is contingent upon the company being in compliance with all applicable listing standards on the date it begins trading on the Exchange, and may be rescinded if the company is not in compliance with such standards. Gran Tierra Energy’s common stock is scheduled to commence trading on the AMEX under the trading symbol “GTE” effective with the opening of the market on Tuesday, April 8, 2008.

The company’s shares will continue to trade on the Toronto Stock Exchange under the symbol “GTE”. Trading on the OTC Bulletin Board will cease upon initiation of trading on the AMEX.

“This is another substantial step forward for Gran Tierra Energy and our shareholders” stated Dana Coffield, Chief Executive Officer of Gran Tierra Energy Inc. “Listing on the AMEX will increase the visibility of the company to the financial community and allow us to continue to diversify our shareholder base. We fully expect our growing operational success to be better reflected and communicated with our listing on the American Stock Exchange,” Coffield concluded.

About Gran Tierra Energy Inc.

Gran Tierra Energy Inc. is an international oil and gas exploration and production company operating in South America, headquartered in Calgary, Canada, incorporated in the United States, and trading on the Toronto Stock Exchange (GTE) and the OTC Bulletin Board (GTRE). Gran Tierra Energy holds interests in producing and prospective properties in Argentina, Colombia and Peru. The company strategy is focused on growing a portfolio of drilling opportunities to exploit undeveloped reserves to increase production, as well as undertaking exploration to grow future reserves. Additional information concerning Gran Tierra Energy is available at www.grantierra.com. Investor inquiries may be directed to info@grantierra.com or 1-800-916-GTRE (4873).