23 Julio 2007

Gran Tierra Energy Announces Award of Two New Blocks In Colombia

Award of Two Technical Evaluation Areas Follows

Recent Discoveries Operated by Gran Tierra Energy

CALGARY, Canada, July 23, 2007 – Gran Tierra Energy Inc. (OTC Bulletin Board: GTRE), a company focused on oil exploration and production in South America, today announced that its application for two Technical Evaluation Areas (TEAs) in the Putumayo Basin in southern Colombia have been approved by the Agencia Nacional de Hidrocarburos (ANH).

The approval of the two TEAs follows the recent announcements of the Costayaco and Juanambu oil discoveries operated by Gran Tierra Energy that tested flow rates up to 5,906 barrels of oil per day and 778 barrels of oil per day respectively. The two TEAs are located near the Orito Field, the largest oil field in the Putumayo Basin. With granting of these two TEA contracts, Gran Tierra Energy will be the largest private exploration license holder in the Putumayo Basin.

Dana Coffield, President and CEO stated “The awards of these two blocks give Gran Tierra Energy an expansive land area to evaluate and apply our acquired knowledge base from our two recent oil exploration discoveries in the Putumayo Basin. This advances our strategy of actively acquiring new assets for evaluation so as to develop an inventory of new opportunities for drilling in the future as our existing inventory of prospects is drilled.”

Putumayo A covers an area of 1,409 square kilometers (570,000 acres) and is to be held 100% by Gran Tierra Energy. The effective date of the contract will be the date the formal contract is signed. The evaluation period is 12 months. During this time, Gran Tierra Energy has an obligation to conduct 400 kilometers of seismic reprocessing and geologic studies. The company will have a preferential right to apply for an Exploration & Production contract in the area during the evaluation stage and match or improve any bid by third parties to convert all or a portion of the TEA to an exploration license.

Putumayo B covers an area of 440 square kilometers (109,000 acres) and is to be held 100% by Gran Tierra Energy. The effective date of the contract will be the date the formal contract is signed. The evaluation period is for 11 months. During this time, Gran Tierra Energy has an obligation to conduct 100 kilometers of seismic reprocessing and geologic studies. Gran Tierra Energy shall have a preferential right to apply for an Exploration & Production contract in the area during the evaluation stage and match or improve any bid by third parties to convert all or a portion of the TEA to an exploration license.

If converted to an Exploration and Production contract through the ANH, the retained acreage would be subject to the new and fiscally attractive ANH royalty/tax contract which includes no additional state participation.

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. Gran Tierra Energy holds interests in producing and prospective properties in Argentina, Colombia and Peru. To date, Gran Tierra Energy has pursued 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. Additional information concerning Gran Tierra Energy is available at http://www.grantierra.com. Investor inquiries may be directed to info@grantierra.com or 1-800-916-GTRE (4873).