Press Releases

TGS Wide Azimuth project update

Houston (21 May 2010) - TGS resumed seismic acquisition of the Justice Wide Azimuth (WAZ) survey in the Gulf of Mexico on 20 May 2010.

The project's progress was previously delayed due to the Deepwater Horizon drilling accident, and the subsequent oil spill and containment efforts in the Gulf of Mexico.

During the three week delay, TGS continued to acquire WAZ multi-client data in an area adjacent to existing TGS WAZ coverage in the Gulf of Mexico.

The WAZ crew is expected to continue acquisition on the Justice project until the survey area is completed which is estimated for July 2010.

TGS will continue to place the safety of its personnel and contractors as the highest priority in conducting its operations.

About TGS

TGS provides multi-client geoscience data to oil and gas Exploration and Production companies worldwide. In addition to extensive global geophysical and geological data libraries that include multi-client seismic data, magnetic and gravity data, digital well logs, production data and directional surveys, TGS also offers advanced processing and imaging services, interpretation products, and data integration solutions.

All statements in this press release other than statements of historical fact are forward-looking statements, which are subject to a number of risks, uncertainties and assumptions that are difficult to predict, and are based upon assumptions as to future events that may not prove accurate. These factors include TGS' reliance on a cyclical industry and principal customers, TGS' ability to continue to expand markets for licensing of data, and TGS' ability to acquire and process data product at costs commensurate with profitability. Actual results may differ materially from those expected or projected in the forward-looking statements. TGS undertakes no responsibility or obligation to update or alter forward-looking statements for any reason.

Sven Børre Larsen

Sven Børre Larsen

Chief Financial Officer

Tel: +47 90 94 36 73

Ellen Munkvold

Ellen Munkvold

IR Coordinator

Tel: +47 97 76 26 25