Gran Tierra Energy to File Form 10-K/A to Restate Financial Statements

No Change in Previously Reported Cash and Equivalents or Revenue

CALGARY, Alberta, May 9 /PRNewswire-FirstCall/ -- Gran Tierra Energy Inc.
(TSX: GTE; Amex: GTE), a company focused on oil exploration and production in
South America, announced today that it will restate the company's financial
statements for previously reported quarters ended March 31, 2007, June 30,
2007 and September 30, 2007 and the years ended December 31, 2007 and 2006.
The company discovered a misclassification of accounts payable and accrued
liabilities resulting in a misstatement of cash flows from operating
activities, with a corresponding offset to cash flows from investing
activities. The restatement will have no effect on the previously reported
net change in cash and cash equivalents and no impact on previously reported
consolidated balance sheets or consolidated statements of operations and
accumulated deficit. The company will file an amendment to its annual report
on Form 10-K for the year ended December 31, 2007 to reflect the restatement.
In the course of preparing its interim financial statements for its
quarterly report on Form 10-Q to be filed with the Securities and Exchange
Commission for the quarter ended March 31, 2008, the company discovered the
misclassification in its 2007 interim financial statements for the previously
reported quarters ended March 31, 2007, June 30, 2007 and September 30, 2007,
and annual financial statements for the years ended December 31, 2007 and
2006. The company is in the process of completing its assessment of this
matter.
As a result, management and the audit committee have concluded that the
company's previously-filed financial statements for the corresponding periods
should not be relied upon. The company plans to file its Form 10-K/A
containing its restated 2007 and 2006 financial statements, and reflecting the
corrections to the financial statements for the interim periods in 2007, on
Monday, May 12, 2008.
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 Toronto Stock Exchange (GTE) and the American
Stock Exchange (GTE), and operating in South America. The company holds
interests in producing and prospective properties in Argentina, Colombia and
Peru. The company 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.
Investor inquiries may be directed to info@grantierra.com or 1-800-916-GTRE
(4873).
Forward Looking Statements:
The statement in this news release regarding the company's expected filing
of its Form 10-K/A on May 12, 2008 is a "forward-looking statement" that is
subject to risks, uncertainties and other factors that could cause a delay in
the filing of the Form 10-K/A. There are a number of important factors that
could cause a delay in the filing of the Form 10-K/A, including the required
reviews of the Form 10-K/A by outside auditors and consultants may take more
time than expected, and Gran Tierra Energy may not be able to obtain all
required consents to the filing by such date. Gran Tierra Energy does not
undertake an obligation to update the forward-looking statement in this
release.
SOURCE Gran Tierra Energy Inc.

Dana Coffield, President & Chief Executive Officer of Gran Tierra Energy,
Inc., 1-800-916-4873, info@grantierra.com; or Investor Relations, Al Palombo
of Cameron Associates, +1-212-554-5488, al@cameronassoc.com, for Gran Tierra
Energy, Inc.