Asker, Norway (16 March, 2009) - TGS-NOPEC Geophysical Company ASA (TGS) announced today the formation of a cooperation agreement with Petroleum Geo-Services ASA (PGS) to combine the previously announced and ongoing TGS Hernando 3D survey and the PGS Discovery Desoto Canyon MC3D survey into one large, seamless, 3D multi-client project in the Desoto Canyon in the Central and Eastern Gulf of Mexico Planning areas.

This joint survey, named Hernando will cover a 365 OCS block area (8,500 square kilometers). More than 225 equivalent blocks have already been recorded by the two companies using one 3D vessel each and a subset of this data is currently available as a fast-track product for use in the March 2009 OCS Lease Sale.

"This joint survey offered by TGS and PGS, and funded by oil companies, allows the application of leading-edge technology from both companies to provide the best image of complex geology in an area of significant interest to our customers in the Gulf of Mexico", said Robert Hobbs, COO of TGS.

Final data from the full survey is expected to be available to clients by the end of 2009.