TGS-NOPEC Concludes Acquisition of Aceca Limited

TGS-NOPEC Geophysical has successfully concluded its acquisition of privately held Aceca Limited. The transaction, previously announced on September 16th, significantly broadens the TGS geoscience knowledge base and will add new multi-client interpretive products and subsurface interpretation consulting services to the TGS product line. Final consideration paid for Aceca included $10.25 million in cash and 71,333 TGS shares, some of which have restrictions as to when they can be sold. No new TGS shares were issued for this transaction.

The Aceca transaction is effective as of January 1st. In calendar year 2005, Aceca had revenue (unaudited) of approximately GBP 5.4 million ($9.3 million) and was profitable. The transaction will add to TGS' growth and profitability in 2006 and onwards.