Gran Tierra Energy Signs Three New Exploration and Exploitation Contracts in Colombia

Repairs to Trans Andean Pipeline Completed by Ecopetrol

Gran Tierra Energy Inc. (NYSE Amex: GTE, TSX: GTE), a company focused on oil exploration and production in South America, today announced that it has signed three Exploration and Exploitation contracts with the National Hydrocarbon Agency totaling 235,264 acres in which Gran Tierra has a 100% working interest.

The Piedemonte Norte Block, encompassing 78,743 acres, lies southwest of the Chaza Block where the Costayaco field is located. The Piedemonte Sur Block, encompassing approximately 73,897 acres, is located immediately west of the Orito Field, the largest oil field in the Putumayo Basin. Further south, the Rumiyaco Block encompasses 82,624 acres in the central Putumayo Basin. These blocks were previously a part of the Putumayo West A and B Technical Evaluation Areas.

"These exploration and exploitation contracts provide Gran Tierra Energy with access to a number of material exploration prospects in regions of the Putumayo Basin that have gone relatively unexplored since the 1980's," said Dana Coffield, President and Chief Executive Officer of Gran Tierra Energy. "The seismic reprocessing we completed in 2008 identified several prospective structures on both Piedemonte blocks that lie on the same geological trend as our Costayaco discovery."

Piedemonte Norte Block (100% working interest, 78,743 acres)

Gran Tierra Energy's work obligations on the Piedemonte Norte Block will be completed in six consecutive phases. The first phase, which must be completed within 12 months, requires Gran Tierra Energy to acquire 70 km of 2D seismic data. Subsequent work phases are also 12 months in length, and include the following work obligations:

    <<
    -   Phase 2 - drill one exploration well to 4,500 feet;
    -   Phase 3 - acquire 70 square kilometers of 3D seismic;
    -   Phase 4 - drill one exploration well to 4,500 feet;
    -   Phase 5 - drill one exploration well to 4,500 feet;
    -   Phase 6 - drill one exploration well to 4,500 feet;

    Piedemonte Sur Block (100% working interest, 73,897 acres)

    Gran Tierra Energy's work obligations on the Piedemonte Sur Block will
also be completed in six consecutive phases. The first must be completed
within 12 months, and requires Gran Tierra Energy to drill one exploration
well to 3,000 feet. Subsequent work phases are also 12 months in length, and
include the following work obligations:

    -   Phase 2 - acquire 55 kilometers of 2D seismic;
    -   Phase 3 - drill one exploration well to 3,000 feet;
    -   Phase 4 - acquire 60 square kilometers of 3D seismic;
    -   Phase 5 - drill one exploration well to 3,000 feet;
    -   Phase 6 - drill one exploration well to 3,000 feet;

    Rumiyaco Block (100% working interest, 82,624 acres)

    Gran Tierra Energy's work obligations on the Rumiyaco Block will be
completed in six consecutive phases as well. Gran Tierra has nine months to
complete the first phase, which requires Gran Tierra Energy to reprocess 60 km
of 2D seismic and acquire 68 km of additional 2D seismic. Subsequent work
phases are 12 months in length, and include the following work obligations:

    -   Phase 2 - drill one exploration well to 8,000 feet;
    -   Phase 3 - drill one exploration well to 8,000 feet or acquire 50
        square kilometers of 3D seismic;
    -   Phase 4 - drill one exploration well to 8,000 feet;
    -   Phase 5 - drill one exploration well to 8,000 feet;
    -   Phase 6 - drill one exploration well to 8,000 feet;
    >>

Operations update

Ecopetrol has completed repairs on the Trans Andean Pipeline and normal production operations are expected to resume shortly. Production testing of Costayaco-7 is ongoing, and is expected to be completed in early July. Costayaco-8 has now reached total depth and well logging operations have begun.

About Gran Tierra Energy Inc.

Gran Tierra Energy Inc. is an international oil and gas exploration and production company, headquartered in Calgary, Canada, incorporated in the United States, trading on the NYSE Amex Exchange (GTE) and the Toronto Stock Exchange (GTE), and operating in South America. Gran Tierra Energy holds interests in producing and prospective properties in Argentina, Colombia and Peru. Gran Tierra Energy has a strategy that focuses on establishing 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.

Forward Looking Statements:

The statements in this news release regarding Gran Tierra Energy's expectations regarding the timing of resumed transportation on the Trans Andean Pipeline, and expected timing for completion of testing of Costayaco-7 are forward looking statements or financial outlook ("forward-looking statements") under the meaning of applicable securities laws, including Canadian Securities Administrators' National Instrument 51-102 Continuous Disclosure Obligations and the United States Private Securities Litigation Reform Act of 1995. These statements are subject to risks, uncertainties and other factors that could cause actual results or outcomes to differ materially from those contemplated by the forward-looking statements. There are a number of important factors that could cause the actual results or outcomes to differ materially from those indicated by the forward-looking statements, including, among others: Gran Tierra Energy's operations are located in South America, and une xpected problems can arise due to guerilla activity, technical difficulties and operational difficulties which impact its testing, drilling and production operations, and transport or sale of its products; and geographic, political and weather conditions can impact testing, drilling and production operations, and the production, transport or sale of its products. Further information on potential factors that could affect Gran Tierra Energy are included in risks detailed from time to time in Gran Tierra Energy's Securities and Exchange Commission filings, including, without limitation, under the caption "Risk Factors" in Gran Tierra Energy's Quarterly Report on Form 10-Q filed May 8, 2009. These filings are available on a Web site maintained by the Securities and Exchange Commission at http://www.sec.gov and on SEDAR at www.sedar.com. The forward-looking statements contained herein are expressly qualified in their entirety by this cautionary statement. The forward-looking sta tements are made as of the date of this press release and Gran Tierra Energy disclaims any intention or obligation to update or revise the forward-looking statements, whether as a result of new information, future events or otherwise, except as expressly required by applicable securities legislation.

SOURCE: Gran Tierra Energy Inc.

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