Secondary listing on Kazakhstan RFCA completed

May 22, 2008

Thursday May 22, 2008 – Almaty, Kazakhstan – Tethys Petroleum Limited (“Tethys” or the “Company”) (TSX: TPL) today announced that the listing of its securities on the Official List of the Regional Financial Centre of Almaty (“RFCA”) Special Trading Floor operated by the Kazakhstan Stock Exchange JSC (“KASE”) has been completed. According to The Resolution of Expert Committee the Ordinary Shares of Tethys Petroleum Limited were included into the official list of RFCA and came into force on May 21, 2008.

JSC Astana Finance acted as sponsor for this listing and responsibilities of the market-maker have been assigned to the JSC “Brokerage Company Astana Finance” (Almaty). This listing is a secondary listing to Tethys’ primary listing on the Toronto Stock Exchange (“TSX”) and maintenance of the Company’s shareholders register system will continue to be carried out by Equity Transfer & Trust Company (Toronto, Canada).

Tethys is the first foreign oil and gas company to be accepted to list on the RFCA. The RFCA was established to promote development of the securities market and integration with the international capital markets and has been endorsed by the President of Kazakhstan. The RFCA special trading floor was established on December 15, 2006. The RFCA is operated by the Kazakhstan Stock Exchange and is based in Almaty, the business centre of Kazakhstan.

Other companies listed on the RFCA include Kazcommertzbank, Halyk Savings Bank of Kazakhstan, Kazakhtelecom JSC and Astana Finance JSC.

Dr. David Robson, Chairman, President and Chief Executive Officer of Tethys, said, “We are excited to commence trading on the RFCA, and to become more fully integrated with both the Kazakh and financial community in Almaty. The listing will allow for direct Kazakh involvement in the countries first private dry gas development, and first foreign oil and gas company.”

Tethys is focused on oil and gas exploration and production activities in Central Asia with activities currently in the Republic of Kazakhstan and more recently the Republic of Tajikistan. This highly prolific oil and gas area is rapidly developing and Tethys believes that significant potential exists in both exploration and in discovered deposits.

This press release contains “forward-looking information” which may include, but is not limited to, statements with respect to our operations. Such forward looking statements reflect our current views with respect to future events and are subject to certain risks, uncertainties and assumptions, including, the risks and uncertainties outlined under the section titles “Risk Factors and Uncertainties” in our prospectus (available at www.sedar.com). Should one or more of these risks materialise, or should underlying assumptions prove incorrect, actual results may vary materially from those anticipated, believed, estimated or expected.

For more information please contact:

Sabin Rossi
Vice President Investor Relations
Tethys Petroleum Limited
TD Canada Trust Tower
161 Bay Street, 27th Floor
Toronto N5J 2S1
Canada

Office: 1-416-572-2065
Fax: 1-416-572-2201
e-mail: info@tethys.gg
website: www.tethyspetroleum.com

Ardak Akanov
Managing Director
PG Communications
Almaty, Samal 2 Business Center Satty
Office phone/fax:: 2 72 88 67, 2 72 82 37, 2 72 77 45
Cell: +77017115604
Email: development@pressclub.kz
Website: www.pressclub.kz