Correction Notice to Press Release Regarding Mandatory Notification of Trades

Mandatory Notification of Trades – Attachment Correction ASKER, NORWAY (28 February 2020) – In February 2019, TGS implemented an Employee Share Purchase Plan (ESPP) pursuant to which eligible employees are allowed to purchase TGS common shares at a discount through payroll deductions.  The ESPP operates in six-month periods, and at the end of each period, employees have the option to purchase stock at a 15% discount to the market price at the time of purchase.  The plan sets a maximum purchase of 100 shares per employee per six-month period.  On February 24, 2020 the following primary insiders purchased shares as participants in the ESPP.  The schedule attached reflects the holdings of the primary insiders following the purchase.   —- Katja Akentieva — 100 shares—- Fredrik Amundsen — 100 shares—- William J.C. Ashby — 100 shares—- Kristian Kuvaas Johansen — 100 shares—- Tana LaDon Pool — 100 shares—- Sven Borre Larsen — 100 shares—- Vivi Suhr Engebretsen — 62 shares 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 informationAll 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 principle 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:Fredrik AmundsenChief Financial Officer Tel: +47 995 89882Email:  Fredrik.Amundsen@tgs.com This information is subject to the disclosure requirements pursuant to Section 5-12 the Norwegian Securities Trading Act  AttachmentCorrected_24.02.20_TGS Shareholding balance primary insiders