Oslo, Norway (29 July 2021) - On period from 23 July 2021 to 28 July 2021, TGS
ASA (TGS) purchased 46,840 own shares on the Oslo Stock Exchange at an average
price of NOK 100.3465 per share. Following the purchase TGS holds 519,515 own
shares, representing 0.443% of the total outstanding shares.

The shares were purchased in connection with the share repurchase announced on
11 February 2021.

+------------------------------------------------------------------------------+
|Overview of transactions                                                      |
+----------------------+------------------+----------------+-------------------+
|Date                  |Aggregated daily  |Weighted average|Total daily        |
|                      |volume (number of |share price per |transaction value  |
|                      |shares)           |day (NOK)       |(NOK)              |
+----------------------+------------------+----------------+-------------------+
|23-Jul-21             |20,000            |100.0586        |2,001,172          |
+----------------------+------------------+----------------+-------------------+
|26-Jul-21             |4,000             |98.4023         |393,609            |
+----------------------+------------------+----------------+-------------------+
|27-Jul-21             |20,000            |100.8688        |2,017,376          |
+----------------------+------------------+----------------+-------------------+
|28-Jul-21             |2,840             |101.4335        |288,071            |
+----------------------+------------------+----------------+-------------------+
|                      |                  |                |                   |
+----------------------+------------------+----------------+-------------------+
|                      |                  |                |                   |
+----------------------+------------------+----------------+-------------------+
|                      |                  |                |                   |
+----------------------+------------------+----------------+-------------------+
|Previously disclosed  |407,575           |126.5859        |51,593,250         |
|buy-backs under the   |                  |                |                   |
|program (accumulated) |                  |                |                   |
+----------------------+------------------+----------------+-------------------+
|Accumulated under the |454,415           |123.8812        |56,293,478         |
|buy-back program      |                  |                |                   |
+----------------------+------------------+----------------+-------------------+
|                                                                              |
+------------------------------------------------------------------------------+
|The issuer's holding of own shares:                                           |
|                                                                              |
|Following the completion of the above transactions, TGS owns a total of       |
|519,515 own shares, corresponding to 0.443% of TGS' share capital.            |
|                                                                              |
|                                                                              |
|                                                                              |
|Appendix:                                                                     |
|                                                                              |
|An overview of all transactions made under the buy-back programme that have   |
|been carried out during the above-mentioned time period is attached to this   |
|report and available at www.newsweb.no.                                       |
+------------------------------------------------------------------------------+

About TGS
TGS provides scientific data and intelligence to companies active in the energy
sector. In addition to a global, extensive and diverse energy data library, TGS
offers specialized services such as advanced processing and analytics alongside
cloud-based data applications and solutions.

For more information, visit TGS.com (http://www.tgs.com) or contact: