Petroleum Geo-Services ASA: Mandatory Notification

December 23, 2016: In the subsequent offering announced by Petroleum Geo-Services ASA ("PGS" or "the Company") Bård Stenberg, Vice President IR & Corporate Communications in PGS has on December 22, 2016 subscribed for 3 000 shares in the subsequent offering at a price of NOK 22.50, of which 438 shares were subscribed for pursuant to granted subscription rights. Upon completion of the subsequent offering, Bård Stenberg will own a total of between 4 347 and 6 909 shares in the Company.

Kai Reith, Vice President Corporate Development in PGS has on December 22, 2016 subscribed for 5 000 shares in the subsequent offering at a price of NOK 22.50, of which 448 shares were subscribed for pursuant to granted subscription rights. Upon completion of the subsequent offering, Kai Reith will own a total of between 4 448 and 9 000 shares in the Company.

Berit Osnes, Senior Vice President MultiClient in PGS has on December 22, 2016 subscribed for 5 000 shares in the subsequent offering at a price of NOK 22.50, of which 1 451 shares were subscribed for pursuant to granted subscription rights. Upon completion of the subsequent offering, Berit Osnes will own a total of between 14 394 and 17 943 shares in the Company.

This information is subject to the disclosure requirements pursuant to section 5 -12 of the Norwegian Securities Trading Act.