15 May 2007


Company to Host Conference Call on May 15, 2007 at 11:00 a.m. Eastern

CALGARY, CANADA, May 10, 2007 – Gran Tierra Energy Inc. (GTRE.OB) today announced that the company’s senior management will discuss the company’s results of operations for the first quarter ended March 31, 2007 during a conference call scheduled for Tuesday, May 15, 2007, at 11:00 a.m. Eastern. The company’s financial results for the first quarter are scheduled to be released earlier that day.

What: Gran Tierra Energy Inc.’s First Quarter 2007 Results Conference Call

When: Tuesday, May 15, 2007, 11:00 a.m. Eastern

Web cast address: http://www.streetevents.comhttp://www.fulldisclosure.com

Dial-in Numbers: (866) 578-5747 (domestic) or 617-213-8054 (international), pass code # 22520344

Contact: Al Palombo, Cameron Associates, (212) 245-8800 Ext. 209,


If you are unable to participate, an audio replay of the call will be available beginning two hours after the call and will be available until 11:59 p.m. on May 22, 2007, by dialing (888286-8010 (domestic) or (617801-6888 (international) using confirmation pass code 26306681. An audio replay of the call will also be available on Gran Tierra’s web site, www.grantierra.com, until the next earnings call.

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 holds interests in producing and prospective properties in Argentina, Colombia and Peru. To date, the Company has pursued a strategy that focuses on establishing a portfolio of producing properties, development and exploration opportunities, through 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).