TGS Repurchase of Shares

ASKER, NORWAY (12 May 2011) - TGS-NOPEC Geophysical
Company ASA ("TGS") has today purchased 125,000 own
shares at an average price of NOK 139.89 per share.

Following the purchase, TGS holds 1,753,151 own
shares, representing 1.69% of the outstanding number
of shares. The transaction is part of the share
buyback program announced by TGS on 5 May 2011. The
buyback program includes a repurchase of up to USD 30
million of TGS shares during 2011. During the period
of 6 May to 31 May, the Board has authorized
management to repurchase up to USD 15 million of
shares as part of this program.

Company summary
TGS-NOPEC Geophysical Company (TGS) provides global
geoscience data products and services to the oil and
gas industry for the exploration and delineation of
hydrocarbon reserves. We design and acquire multi-
client data projects worldwide that make up our data
library of seismic, gravity/magnetic and well data,
enhanced by our seismic imaging technology and
regional interpretation expertise. Visit TGS online
at www.tgsnopec.com.

TGS-NOPEC Geophysical Company ASA is listed on the
Oslo Stock Exchange (OSLO:TGS).