TGS ASA

Major Shareholding Notification • Jul 1, 2024

UBS Group AG Postfach 8098 Zürich Tel. +41-44-438 11 11

Global Shareholder Reporting Group Compliance, Regulatory & Governance

www.ubs.com

Registered Strictly confidential

Oslo Børs Box 460 Sentrum 0105 Oslo Norway

July, 1 st 2024

TGS ASA - Disclosure of large shareholdings under the Securities Trading Act

Dear Sir or Madam,

We would like to inform you that UBS Group AG has crossed above 5% of the voting rights and of the share capital in the issuer TGS ASA (NO0003078800). Please let this serve you as our disclosure as set forth below:

Name of the person obliged to notify: UBS Group AG

Residing at: Bahnhofstrasse 45 CH-8001 Zurich Date of event: 28 th June 2024

Event triggering the notification: Acquisition of equity shares

.

Total new holding: 7,578,005 representing 5.78% of the 131,035,143 voting rights and of the share capital out of which 4,932,315 are held in shares equivalent to 3.76% and 2,645,690 equivalent to 2.02% held as financial instruments. The shares are held indirectly by UBS Group AG and directly by its subsidiaries: UBS AG, UBS Switzerland AG, UBS Europe SE, UBS Securities LLC, UBS Asset Management (UK) Limited, UBS Fund Management (Switzerland) AG, UBS Asset Management Switzerland AG, UBS Fund Management (Luxembourg) S.A., UBS Asset Management (Deutschland) GmbH, UBS Asset Management (Singapore) Ltd & Credit Suisse (Schweiz) AG.

This notification has also been sent to the issuer.

If you have any questions regarding this disclosure, please contact Georgaki, Konstantina on +41-44- 239 40 71 in Zurich.

TGS ASA - Disclosure of large shareholdings July 1st , 2024 Page 2 of 2

Yours faithfully,

UBS Group AG

Konstantina Georgaki Sjoerd Sluimer Director Authorized Officer