ASKER, NORWAY (21 May 2019) Following the announcement on 20 May 2019 concerning the merger plan between TGS-NOPEC Geophysical Company ASA and Spectrum ASA, an extraordinary general meeting (EGM) of TGS will be held on 21 June 2019 at the offices of the law firm, Schjødt, at Ruseløkkveien 16, in Oslo at 17:00 CET.

Registration of attendees will begin at 16:30 CET.

The notice for the EGM is available here (in English and Norwegian), together with relevant appendices. The notice will be sent to all registered shareholders as of 20 May 2019.

To register your attendance, send a proxy, or to cast your vote electronically in advance through VPS Investor Services, please use the electronic link here and which is available on www.tgs.com. The pin code and reference number - which will be sent out with the notice - will be required. Kindly note that any shareholders that have received the notice electronically will not receive and do not require a pin code or reference number, but must submit their notice of attendance, proxy or advance votes through their online investor account services (investortjenester).

Online registration will open on 22 May 2019 at 14:00 CET.