TGS ASA — Share Issue/Capital Change 2018

May 23, 2018

TGS : Stock options exercised

TGS : Stock options exercised

ASKER, NORWAY (23 May 2018) - 16 option holders have today, exercised in total

129,500 stock options. All the options were exercised from the award in August

2013 secured by warrants at an exercise price of NOK 181.90 per share.

The following primary insiders in TGS have on 23 May 2018 traded TGS shares

related to their exercise of stock options:

Kristian Johansen, Chief Executive Officer, has exercised 12,000 stock options

and sold 6,000 shares in TGS at an average price of NOK 273.80 per share. After

this transaction, Kristian Johansen holds 26,200 shares in TGS.

Fredrik Amundsen, Senior Vice President Europe and Asia Pacific, has exercised

10,100 stock options and sold the same number of shares in TGS at an average

price of NOK 273.80 per share. Fredrik Amundsen holds 2,250 shares in TGS.

Tom Neugebauer, Director of Project Development NSA, has exercised 2,500 stock

options and sold the same number of shares in TGS at an average price of NOK

273.80 per share. Tom Neugebauer does not hold any shares in TGS.

Attached is the list of the primary insiders exercising stock options.

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, 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 to the disclosure requirements pursuant to section

5-12 of the Norwegian Securities Trading Act.