Execution of Supplemental Indentures

Paris, France | Feb 23, 2017

On February 6, 2017, CGG S.A. (“CGG”) announced a consent solicitation in respect of its Senior Notes (the “Notes Solicitation”). The purpose of the Notes Solicitation was to permit CGG to amend the indentures in respect of the Senior Notes to provide CGG the option to request the appointment of a ‘mandataire ad hoc’ (a French facilitator for creditor negotiations) without such action constituting an Event of Default under the indentures. The proposed indenture amendments also provided for certain information undertakings by CGG.

As disclosed on February 20, 2017, CGG (i) successfully completed the consent solicitation in respect of its 2020 Notes, 2021 Notes and 2022 Notes by receiving consent from the requisite majority of the holders of such notes and (ii) extended the consent solicitation in respect of its 2017 Notes (the “2017 Notes Solicitation Extension”).

CGG today announces that the Effective Time, as defined in the Consent Solicitation Statement dated February 3, 2017 (the “Consent Solicitation Statement”), occurred on February 22, 2017, as the supplemental indentures in respect of the 2020 Notes, the 2021 Notes and the 2022 Notes giving effect to the amendments proposed in the Consent Solicitation Statement were executed by the parties thereto and became effective in accordance with their terms.

CGG also announces that the 2017 Notes Solicitation Extension has expired without receipt of the requisite majority of holders of such notes. CGG intends to discharge and satisfy the indenture in respect of the 2017 Notes in accordance with its terms (through the payment of the aggregate outstanding principal ($8,319,000) and interest on the 2017 Notes to the indenture trustee in trust for the bondholders) no later than Friday, February 24, 2017. CGG further intends to request the appointment of a mandataire ad hoc as soon as practicable thereafter.

“Senior Notes” means CGG’s 7.750% Senior Notes due 2017 (CUSIP: 204386AK2 / ISIN: US204386AK24) (the “2017 Notes”), 6.500% Senior Notes due 2021 (CUSIP: 204384AB7 / ISIN: US204384AB76; CUSIP: F1704UAD6 / ISIN: USF1704UAD66) (the “2021 Notes”), 5.875% Senior Notes due 2020 (Reg. S ISIN: XS1061175607 / Reg. S Common Code: 106117560; Rule 144A ISIN: XS1061175862 / Rule 144A Common Code: 106117586) (the “ 2020 Notes”) and 6.875% Senior Notes due 2022 (Reg. S CUSIP: F1704UAC8 / Reg. S ISIN: USF1704UAC83; Registered CUSIP: 12531TAB5 / Registered ISIN: US12531TAB52)(the “2022 Notes”).