Mandatory notification of trade ASKER, NORWAY (

ASKER, NORWAY (4 August 2017) - Kristian Johansen, CEO of TGS-NOPEC Geophysical Company ASA ('TGS'), has today bought 1,200 shares in TGS at a price of NOK 165.28 per share.  Following this transaction, Mr. Johansen holds 15,700 shares, 24,500 options and 88,000 Performance Share Units in TGS.

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 (OSLO: TGS ).

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:

Sven Børre Larsen Chief Financial Officer Tel: +47 90 94 36 73 Email: sven.larsen@tgs.com

Will Ashby VP HR & Communication Tel: +1 713 860 2184 Email: will.ashby@tgs.com

This information is subject of the disclosure requirements acc. to §5-12 vphl (Norwegian Securities Trading Act).