24 November 2008

Gran Tierra Energy Announces Temporary Suspension of Production Operations in its Costayaco and Juanambu Oil Fields, Colombia

CALGARY, Alberta – November 24, 2008 – Gran Tierra Energy Inc. (AMEX: GTE; TSX: GTE) a company focused on oil exploration and production in South America, today announced that it has temporarily suspended production operations in the Costayaco and Juanambu oil fields in the Putumayo Basin of southern Colombia. Production from other assets in the Putumayo Basin, the Llanos Basin and the lower Magdalena Basin continues unimpeded.

This temporary suspension of production operations is the result of a declaration of a state of emergency and force majeure by Ecopetrol, the Colombian National Oil Company, due to a general strike in the region. The resumption of crude oil deliveries to Orito is pending resolution of the strike and evaluation of the condition of oil pipelines in the region. The Colombian government is actively working with municipality leaders to resolve the general strike as quickly and efficiently as possible. Gran Tierra Energy is in regular contact with the appropriate authorities to monitor the situation.Commenting on the circumstances, Dana Coffield, President and Chief Executive Officer of Gran Tierra Energy, stated, “We expect successful resolution of the general strike and resumption of crude transportation shortly and remain positioned to continue our production growth from our assets in the Putumayo region.”

Appropriate safeguards have been implemented that Gran Tierra Energy believes will ensure the safety and security of the company’s assets and employees. This suspension of production operations has had no impact on drilling operations. Costayaco-6 was drilled and completed prior to the strike, with testing operations remaining on the schedule for December. Costayaco-7 is not scheduled to begin drilling until completion of the drilling location which is now scheduled for late December.

About Gran Tierra Energy Inc.

Gran Tierra Energy is an international oil and gas exploration and production company operating in South America, headquartered in Calgary, Canada and incorporated in the United States. 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. Gran Tierra Energy trades on the American Stock Exchange under the symbol “GTE” and on the Toronto Stock Exchange under the symbol “GTE”.

Additional information concerning Gran Tierra is available at www.grantierra.com , on SEDAR (www.sedar.com) and with the Securities and Exchange Commission (www.sec.gov).

Forward Looking Statements

The statements in this press release regarding Gran Tierra Energy’s beliefs that the safety and security of its assets are ensured, that testing operations on Costayaco-6 is on schedule for testing in December, and the timing of drilling Costayaco-7, are “forward-looking statements” within the meaning of the U.S. federal and Canadian securities laws, including Canadian Securities Administrators’ National Instrument 51-102 Continuous Disclosure Obligations and the U.S. Private Securities Litigation Reform Act of 1995.

Factors that could cause results to differ materially from those described in the forward-looking statements include: the strike and state of emergency may continue for longer than Gran Tierra Energy expects, which could impact Gran Tierra Energy’s ability to complete testing and drilling on schedule and may also impact production; heightened unrest could imperil the safety and security of Gran Tierra Energy’s assets and personnel despite the safety measures Gran Tierra Energy has put in place to address the current situation, which could also delay the testing and drilling and could also impact production; and those other risks found in the periodic reports filed by Gran Tierra with the Securities and Exchange Commission, including in the section entitled “Risk Factors” in its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 6, 2008, and available at the Securities and Exchange Commission’s internet site www.sec.gov and on SEDAR at www.sedar.com.

All forward-looking statements in this press release are expressly qualified by information contained in each company’s filings with regulatory authorities and, subject to its obligations under applicable securities laws, Gran Tierra Energy does not undertake to publicly update forward-looking statements, whether as a result of new information, future events or otherwise.