CGG

Proxy Solicitation & Information Statement • Nov 7, 2017

Update of the voting form

Paris, France – November 7, 2017

CGG updated its voting form for the purpose of the extraordinary general meeting convened on second notice on November 13, 2017 (available via the following link), which states that, to be taken into account, it must be received by BNP PARIBAS SECURITIES SERVICES, CTS Assemblées, Grands Moulins de Pantin – 93761 PANTIN Cedex by 3:00 p.m. (Paris time) on November 10, 2017 at the latest.

The shareholders of CGG are invited to mobilize to participate in the general meeting to be held on November 13, 2017 (in accordance with the terms specified in the second convening notice published in the BALO No. 132 dated November 3, 2017, which include inter alia the use of the voting form).

About CGG:

CGG (www.cgg.com) is a fully integrated Geoscience company providing leading geological, geophysical and reservoir capabilities to its broad base of customers primarily from the global oil and gas industry. Through its three complementary businesses of Equipment, Acquisition and Geology, Geophysics & Reservoir (GGR), CGG brings value across all aspects of natural resource exploration and exploitation. CGG employs around 5,500 people around the world, all with a Passion for Geoscience and working together to deliver the best solutions to its customers.

CGG is listed on the Euronext Paris SA (ISIN: 0013181864) and the New York Stock Exchange (in the form of American Depositary Shares. NYSE: CGG).

Contacts Group Communications Christophe Barnini Tel: + 33 1 64 47 38 11 E-Mail: : invrelparis@cgg.com

Investor Relations Catherine Leveau Tel: +33 1 64 47 34 89 E-mail: : invrelparis@cgg.com