Asker, Norway (March 25, 2009) - The Board of Directors of TGS-NOPEC Geophysical Company ("TGS" or the "Company") announced today the following planned changes in leadership to become effective following the Company's Annual General Meeting on June 4, 2009:

Claus Kampmann will retire as Chairman and Director. Claus was first elected to the Board in 2002 and has served as its Chairman since 2004.

Hank Hamilton will retire as Chief Executive Officer. He will continue with TGS as a non-executive advisor and will be proposed by the current Nomination Committee for election as the new Chairman of TGS. Hank has served as the Chief Executive Officer of TGS since 1995 and as a Director since 1998.

Robert Hobbs will become Chief Executive Officer of TGS. Robert joined TGS in January 2008 as the Chief Operating Officer. Prior to joining TGS, Robert was Manager, Worldwide Geoscience with Marathon Oil Company. Earlier in his career, Robert spent nine years with Veritas DGC in a wide range of roles including President & Managing Director of the company's wholly owned UK subsidiary, where he was responsible for all product lines in the Europe, Africa, Middle East, and former Soviet Union region. He also worked ten years as both a geologist and a geophysicist with ARCO Oil and Gas, Exxon, and Union Texas Petroleum. He holds a M.Sc. degree in Geology from the University of Southern California.

"These changes are in line with the Board's long term succession plan and with Hank's and my personal desires. I am convinced that with our experienced management team, with Robert, Hank and our Directors, we will be stronger than ever and will have the best team in our industry" stated Claus Kampmann.

Hank Hamilton commented "As a shareholder and Director I am very grateful for Claus's dedicated service and leadership over the past seven years. I have full confidence in Robert Hobbs as our new Chief Executive and I look forward to serving TGS in a different role, where I can focus more on strategic, long-term development initiatives."