Companies to Host Joint Investor Conference Call on Tuesday July 29, 2008

                           at 11:00 a.m. Eastern



    CALGARY, Alberta, July 29 /EMWNews/ -- Gran Tierra Energy

Inc. (Amex: GTE; TSX: GTE) and Solana Resources Limited (TSX-V: SOR; AIM:

SORL) announced today that they have entered into a definitive agreement

providing for the business combination of Gran Tierra Energy Inc. and

Solana Resources Limited. The transaction is expected to create an

exploration and production company with a significantly increased operating

scale and balance sheet.



    Mr. Dana Coffield, President and Chief Executive Officer of Gran

Tierra, will continue as the President and Chief Executive Officer of the

combined company, while Mr. J. Scott Price, President and Chief Executive

Officer of Solana, will join the board of directors of the combined

company. The board of directors will be comprised of seven members

including the current directors of Gran Tierra: Jeffrey Scott, Walter

Dawson, Verne Johnson, Nick Kirton, and Dana Coffield, as well as Scott

Price, and the current Chairman of the Solana board of directors, Mr. Ray

Antony. Mr. Scott, Chairman of the Gran Tierra board of directors, will

maintain his position as Chairman.



    Commenting on the transaction Mr. Coffield stated, "We are very pleased

to make this announcement and we expect the transaction will create a much

more substantial company in a consolidating global industry while

preserving Gran Tierra's operating leadership. The combination creates a

company with a 100 percent working interest in one of the most important

oil discoveries in Colombia in recent years, the Costayaco field. The

anticipated production and cash flow growth from Colombia will fund

continued exploration on the resulting company's combined land position, in

addition to increasing the capability to undertake much larger and material

new venture initiatives in the future."



    Mr. Price stated, "The combination of the two companies will not only

consolidate a premium light oil asset in Colombia, but will also launch a

substantive, well financed, South American focused entity with an enviable

land position and a portfolio of opportunities across the risk spectrum. We

believe this transaction will result in significant value accruing from the

asset consolidation and resultant economies of scale."



    Summary of the Transaction



    Under the terms of the Agreement, each Solana shareholder will receive

either (i) 0.9527918 of a common share of Gran Tierra or; (ii) 0.9527918 of

a common share of a Canadian subsidiary of Gran Tierra (an "Exchangeable

Share") for each common share of Solana held, which represents a premium of

approximately 14.1 % to the 20 day weighted average trading price to July

28, 2008 of the Solana shares on the TSX Venture Exchange and Gran Tierra's

July 28, 2008, closing price on the Toronto Stock Exchange of CAD $5.73.

The shares of the Canadian subsidiary of Gran Tierra: (i) will have the

same voting rights, dividend entitlements and other attributes as Gran

Tierra common stock; (ii) will be exchangeable, at each shareholder's

option, on a one-for-one basis, into Gran Tierra common stock; and (iii)

subject to compliance with the listing requirements of the Toronto Stock

Exchange, will be listed on the Toronto Stock Exchange. The Exchangeable

Shares will automatically be exchanged for Gran Tierra common stock five

years from closing, and in certain other events.



    The transaction will be completed pursuant to a statutory plan of

arrangement pursuant to the Business Corporations Act (Alberta). Upon

completion of the transaction, Solana will become an indirect wholly-owned

subsidiary of Gran Tierra. The plan of arrangement will be accomplished on

a tax deferred basis in Canada, but may be a taxable transaction for non-

Canadian holders of Solana securities. On a fully diluted basis, upon the

closing of the plan of arrangement, Solana securityholders will own

approximately 49% of the combined company and Gran Tierra securityholders

will own approximately 51% of the combined company.



    The proposed transaction is subject to regulatory, stock exchange,

court and shareholder approvals. Gran Tierra and Solana expect to hold

shareholder meetings in October 2008. A joint proxy statement and

management information circular is expected to be mailed to shareholders of

the companies in September 2008. The parties have agreed to pay each other

a termination fee of $21 million in certain circumstances and an expense

reimbursement fee of $1.5 million in certain other circumstances.



    Complete details of the plan of arrangement are set out in the

agreement, which will be filed by Solana on SEDAR (http://www.sedar.com) and Gran

Tierra on SEDAR and with the Securities and Exchange Commission

(http://www.sec.gov).



    Following the offer becoming or being declared unconditional in all

respects and as soon as it is able to do so (subject to any applicable

requirements of the AIM Rules), Gran Tierra will procure that Solana will

apply to the London Stock Exchange for the cancellation of the admission of

Solana shares to trading on AIM. A notice period of not less than 20

business days prior to the cancellation of trading will take effect upon

the offer becoming or being declared unconditional in all respects.

Cancellation of admission to trading on AIM is likely to reduce

significantly the liquidity and marketability of any Solana shares in

respect of which the offer has not been accepted. Gran Tierra will also

seek to have the Solana shares delisted from the TSX Venture Exchange and

to cease Solana being a reporting issuer under applicable Canadian

securities laws.



    Highlights of the Combined Entity



    Management of Gran Tierra and Solana expect that the combination will

provide many benefits, including the following:



    -- Creation of a stronger South American oil producer with significant

producing assets in Colombia;



    -- Significant exploration portfolio properties in each of Colombia,

Argentina and Peru;



    -- Consolidation of 100% of the working interest in the Costayaco field

(95% economic interest excluding government royalties), a major light oil

discovery made in Colombia in 2007, currently under delineation and

development;



    -- An entity with a pro-forma enterprise value of approximately $1.35

billion based on Gran Tierra's stock price on July 28, 2008, which is

expected to result in enhanced liquidity and a more competitive cost of

capital; and



    -- Strong pro-forma cash flows which are expected to allow the combined

entity to internally finance the exploration and development of the

Costayaco field, pursue other exploration opportunities on the combined

company's large undeveloped land base in Colombia, Argentina and Peru, and

pursue additional new venture growth opportunities.



    Key Pro Forma Operating and Financial Information for the Combined

Entity



    Some of the key pro forma and financial metrics for the combined

company include the following:(1)






    Estimated Combined 2008 Exit Production         15,000 boe/d

    Pro-forma enterprise value (2)                  $1.35 billion

    Fully diluted shares outstanding                268.3 million

    Pro-forma proven reserves(3)                    18.4 MMboe

    Pro-forma land base(4)

           Colombia                                 1.5 million acres

           Argentina                                1.3 million acres

           Peru                                     3.4 million acres



    Notes:

    (1) Represents current estimates of Gran Tierra and Solana management and

        is disclosed net after all royalties; "boe/d" is barrels of oil

        equivalent per day.

    (2) Pro-forma enterprise value is equal to pro-forma fully diluted market

        capitalization plus estimated pro-forma net debt; pro-forma market

        capitalization is calculated based on July 28, 2008 Gran Tierra

        closing share price on the Toronto Stock Exchange of CAD $5.73

        converted at today's closing CAD/USD exchange rate

        of 1.0226; estimated net debt is calculated as debt less working

        capital and proceeds from the exercise of in-the-money dilutive

        instruments.

    (3) Represents the sum of the independent reserves reports for Gran Tierra

        and Solana as at December 31, 2007, updated to reflect the mid-year

        2008 reserve report for Costayaco prepared by GLJ Petroleum

        Consultants at the request of Gran Tierra, reported in millions of

        barrels of oil equivalent "MMboe" net after royalties.

    (4) Represents the approximate net acreage for Gran Tierra and Solana,

        based on management's current estimates.

    Mr. Glenn Van Doorne, Chief Operating Officer of Solana, a Petroleum

Geologist, and Mr. Dana Coffield, President and CEO of Gran Tierra, a

Geologist, are the qualified persons who have reviewed the technical

information contained in this news release.



    Advisors



    Blackmont Capital Inc. is acting as exclusive financial advisor to Gran

Tierra with respect to the transaction and has verbally advised the board

of directors of Gran Tierra that it is of the opinion, as of the date

hereof, that the consideration to be offered by Gran Tierra pursuant to the

proposed combination is fair, from a financial point of view, to Gran

Tierra shareholders.



    Tristone Capital Inc. is acting as exclusive financial advisor to

Solana with respect to the transaction and has verbally advised the board

of directors of Solana that it is of the opinion, as of the date hereof,

that the consideration to be received by Solana shareholders is fair, from

a financial point of view, to Solana shareholders.



    Conference Call Information:



    Gran Tierra and Solana will hold a joint conference call to review the

transaction on Tuesday, July 29, 2008 at 11:00 a.m. Eastern Daylight Time.

The call will be hosted by Mr. Dana Coffield, President and Chief Executive

Officer of Gran Tierra, and Mr. Scott Price, President and Chief Executive

Officer of Solana Resources. Interested parties may access the conference

call by dialing (888) 713-4213 (domestic) or (617) 213-4865

(international), pass code # 95621291. The call will also be available via

web cast at http://www.grantierra.com, or http://www.streetevents.com, or

http://www.fulldisclosure.com



    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 August 4, 2008, by dialing (888) 286-8010 (domestic) or (617)

801-6888 (international) using confirmation pass code 74702931.

    About Gran Tierra Energy Inc.:



    Gran Tierra is an international oil and gas exploration and production

company operating in South America, headquartered in Calgary, Canada and is

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 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

http://www.grantierra.com, on SEDAR (http://www.sedar.com) and with the Securities and

Exchange Commission (http://www.sec.gov).



    About Solana Resources Limited:



    Solana is an international resource company engaged in the acquisition,

exploration, development and production of oil and natural gas. The

company's properties are located in Colombia, South America and are held

through its wholly owned subsidiary, Solana Petroleum Exploration

(Colombia) Limited. The Company is headquartered in Calgary, Alberta,

Canada. Solana trades on the TSX Venture Exchange under the symbol "SOR"

and on the AIM Exchange under the symbol "SORL".



    Additional information concerning Solana is available at

http://www.solanaresources.com and on SEDAR (http://www.sedar.com)



    Barrels of Oil Equivalent



    Barrels of oil equivalent (boe) is calculated using the conversion

factor of 6,000 cubic feet ("6Mcf") of natural gas being equivalent to one

barrel of oil. Boes may be misleading, particularly if used in isolation. A

boe conversion ratio of 6 Mcf per barrel is based on an energy equivalency

conversion method primarily applicable at the burner tip and does not

represent a value equivalency at the wellhead.



    Forward Looking Statements:



    This press release includes "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. Forward-looking statements are commonly identified by such

terms and phrases as "would", "may", "will", "anticipates", "expects" or

"expected to" and other terms with similar meaning indicating possible

future events or actions or potential impact on the businesses or

shareholders of Gran Tierra Energy Inc. and Solana Resources Limited. Such

statements include, but are not limited to, statements about the

anticipated benefits, savings and synergies of the plan of arrangement,

including future financial and operating results, the plans, objectives,

expectations and intentions of the combined company, the future development

of the combined company's business, and the contingencies and uncertainties

to which Gran Tierra and Solana may be subject prior to closing the

transaction and other statements that are not historical facts. The press

release also includes information that has not been reviewed by the

independent auditors of Gran Tierra or Solana. There is no assurance that

the proposed transaction contemplated in this press release will be

completed at all, or completed upon the same terms and conditions

described.



    The following factors, among others, could cause actual results to

differ materially from those set forth in the forward-looking statements:

the ability to obtain required approvals of the plan of arrangement on the

proposed terms and schedule; the failure of the shareholders of Solana to

approve the plan of arrangement or the shareholders of Gran Tierra to

approve the issuance of the Gran Tierra shares to the holders of Solana

securities in the proposed transaction; the risk that the businesses will

not be integrated successfully; the risk that the cost savings and any

revenue synergies from the plan of arrangement may not be fully realized or

may take longer to realize than expected; and disruption from the

transaction making it more difficult to maintain relationships with

regulatory agencies, employees or suppliers. Additional factors that could

cause results to differ materially from those described in the

forward-looking statements can be found in the periodic reports filed by

Gran Tierra with the Securities and Exchange Commission and available at

the Securities and Exchange Commission's internet site http://www.sec.gov and on

SEDAR at http://www.sedar.com, as well as Solana's continuous disclosure documents

filed on Solana's SEDAR profile at http://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 their obligations under applicable

securities laws, neither company undertakes to publicly update

forward-looking statements, whether as a result of new information, future

events or otherwise.



    Additional Information



    Shareholders are urged to read the joint proxy statement/management

information circular regarding the proposed transaction and the

registration statement filed on Form S-3 by Gran Tierra when they become

available, because they will contain important information. Shareholders

will be able to obtain a free copy of the joint proxy statement/management

information circular, as well as other filings including the registration

statement on Form S-3 containing information about Gran Tierra, without

charge, at the Securities and Exchange Commission's internet site

http://www.sec.gov. Copies of the joint proxy statement and the filings with the

Securities and Exchange Commission that will be incorporated by reference

in the joint proxy statement and registration statement on Form S-3 can

also be obtained, without charge, by directing a request to Gran Tierra at

1-800-916-4873.



    The respective directors and executive officers of Gran Tierra and

Solana and other persons may be deemed to be participants in the

solicitation of proxies in respect of the proposed transaction. Information

regarding Gran Tierra's directors and executive officers is available in

the 2007 Annual Report on Form 10-K/A filed with the Securities and

Exchange Commission by Gran Tierra on May 12, 2008, and information

regarding Solana's directors and executive officers will be included in the

joint proxy statement/management information circular. Other information

regarding the participants in the proxy solicitation and a description of

their direct and indirect interests, by security holdings or otherwise,

will be contained in the joint proxy statement and other relevant materials

to be filed with the Securities and Exchange Commission when they become

available.



    No regulatory authority has approved or disapproved the content of this

release. Neither the TSX Venture Exchange nor the Toronto Stock Exchange

accepts responsibility for the adequacy or accuracy of this release.






     Gran Tierra Energy Inc.    Solana Resources Limited   Al Palombo

     Dana Coffield              J. Scott Price             Cameron Associates

     President & Chief          President & Chief          Investor Relations

     Executive Officer          Executive Officer

     (800) 916-4873             (403) 770-1822             (212) 554-5488

     info@grantierra.com        jsp@solanaresources.com    al@cameronassoc.com