ASKER, NORWAY (26 August 2014) - TGS announces acquisition of a 3D multi-client survey offshore Sierra Leone. The survey, Sierra Leone Block 4A Extension, will add 1,000 km² of new 3D data to the existing 6,268 km² of 3D data library in Sierra Leone.

"This survey extends our current data coverage in an important and prospective area. TGS has been active in acquiring data over the West Africa Transform Margin for the past decade and we are pleased with the level of customer support to continue our investment in this region," commented Stein Ove Isaksen, Senior VP Eastern Hemisphere for TGS.

TGS is chartering the 12 streamer Polarcus Alima for this survey. Data processing will be performed by TGS and will be available to clients in Q1 2015.

The survey is supported by industry funding.

To view TGS` updated vessel and crew capacity schedule, please click here.

Company summary

TGS-NOPEC Geophysical Company (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, permanent reservoir monitoring and data integration solutions.

For more information visit TGS online at www.tgs.com.

Forward-looking statements and contact information

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 products 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.

TGS-NOPEC Geophysical Company ASA is listed on the Oslo Stock Exchange (TGS.OL).

TGS sponsored American Depositary Shares trade on the U.S. over-the-counter market under the symbol "TGSGY".

For additional information about this press release please contact:

Kristian Johansen
Chief Financial Officer
Tel: +47 47 60 33 34
Email: kristian.johansen@tgs.com