Increases Equity Stake in Gulf of Mexico 3D Portfolio, Launches New 3D Pre-Stack Time Migration Project

TGS-NOPEC Geophysical Company announced today that it has acquired 100% ownership in 8,800 square kilometers of non-exclusive 3D data previously owned jointly with WesternGeco. Under terms of the agreement with WesternGeco, TGS-NOPEC exchanged its interest in four other jointly held Gulf of Mexico 3D surveys and paid an undisclosed amount of cash to acquire WesternGeco's share of eight 3D surveys located within TGS-NOPEC's "Pangaea' complex of 3D surveys on the offshore Louisiana shelf.

According to Karen El-Tawil, TGS-NOPEC's Vice President of Gulf of Mexico, "This transaction stems from the desire of both companies to rationalize Gulf of Mexico 3D assets following the merger of Western Geophysical and Geco-Prakla.'

In a related development, TGS-NOPEC also announced today that it has commenced a new 3D pre-stack time migration project covering the entire 14,300 square kilometer Pangaea area. The project is designed with the latest Kirchoff migration technology in an effort to improve imaging deeper in the subsurface where new exploration efforts are focused. Deliverables in addition to the final migrated product will include pre-stack gathers and a number of specific AVO products. The project is strongly supported by industry pre-funding. To view a map of the Pangaea area, visit the TGS-NOPEC web site at: www.tgsnopec.com.

TGS-NOPEC is a leading global provider of non-exclusive seismic data and associated products to the oil and gas industry. Oil companies use this seismic data to explore for and develop oil and gas deposits. TGS-NOPEC specializes in the planning, acquisition, processing, interpretation, and marketing of non-exclusive surveys worldwide. The company places a strong emphasis on providing high quality seismic data and the highest level of service to the industry. TGS-NOPEC also offers proprietary seismic acquisition and processing services, as well as gravity and aeromagnetic surveys.

TGS-NOPEC is listed on the Oslo Stock Exchange (OSLO:TGS).