CGG Partially Redeem its US$ 225 Million Senior Notes

The meeting the Board of Directors of CGG (ISIN : FR0000120164 ; NYSE : GGY) held on December 8, 2004 authorized the company to partially redeem its US$ 225 million 10 5/8% Senior Notes, up to US$ 75 million. Such redemption implies the payment of an early reimbursement fee corresponding to a six-month interest of 5.3125% of the total redemption amount, i.e. $3.984.37. The redemption of the notes shall actually take place on January 26, 2005.

The information included herein contains certain forward-looking statements within the meaning of Section 27A of the securities act of 1933 and section 21E of the Securities Exchange Act of 1934. These forward-looking statements reflect numerous assumptions and involve a number of risks and uncertainties as disclosed by the Company from time to time in its filings with the Securities and Exchange Commission. Actual results may vary materially.