Gran Tierra Energy Announces Filing of NI 51-101 Reserves Disclosures

Gran Tierra Energy Inc. (NYSE Alternext: GTE, TSX: GTE), a company focused on oil exploration and production in South America, today announced it has filed information regarding the company's crude oil and natural gas reserves for the year ended December 31, 2008 in accordance with the requirements of Canadian Securities Administrators' National Instrument 51-101 Standards of Disclosure for Oil and Gas Activities.

Gran Tierra Energy's Statement of Reserves Data and Other Oil and Gas Information Form NI 51-101 F1; Report on Reserves Data by Independent Evaluator Form 51-101 F2; and Report of Management and Directors on Reserves Data and Other Information Form 51-101 F3; are now accessible on www.sedar.com.

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 NYSE Alternext (GTE) and the Toronto Stock Exchange (GTE). The company holds interests in producing and prospective properties in Colombia, Argentina, and Peru. The company has a strategy that focuses on growing a portfolio of producing properties, plus production enhancement and exploration opportunities to provide a base for future growth. Additional information concerning Gran Tierra Energy is available at www.grantierra.com. Investor inquiries may be directed to [email protected] or 1-800-916-GTRE (4873).

Gran Tierra Energy's Securities and Exchange Commission filings are available on a Web site maintained by the Securities and Exchange Commission at http://www.sec.gov and on SEDAR at http://www.sedar.com.

Contacts:

Dana Coffield Al Palombo
Gran Tierra Energy Inc. Cameron Associates
President & Chief Executive Officer Investor Relations
(866) 973-4873 (212) 245-8800 Ext. 209
[email protected] [email protected]

SOURCE: Gran Tierra Energy Inc.

Dana Coffield, President & Chief Executive Officer of Gran Tierra Energy Inc.,
1-866-973-4873, [email protected]; or Al Palombo, Investor Relations of Cameron Associates, +1-212-245-8800, ext. 209, [email protected], for Gran Tierra Energy Inc. Web Site: http://www.grantierra.com