Asker, Norway (16 September, 2009) - TGS-NOPEC Geophysical Company (TGS) announced today that it has signed an agreement with the National Oil Company of Liberia ("NOCAL") to acquire 15,000 kilometers of long-offset regional 2D seismic, gravity, and magnetic data over the ultra-deep waters located offshore Liberia. This new multi-client survey is expected to commence in the fourth quarter of 2009, given sufficient industry interest. Offshore Liberia has attracted significant industry attention due to recently announced discoveries in the Gulf of Guinea.

"TGS has been acquiring data along this margin since 2000 and is pleased to expand our data coverage in Liberia. It has been extremely rewarding to see the value being generated from our activities for both the local region and the oil and gas industry in general over this extended period," said David Hicks, VP of Africa, Middle East and Far East for TGS.

The Liberia Ultra-Deep Program will extend existing TGS multi-client data out to 4000 meters of water. NOCAL is expected to announce a licensing round following the acquisition and processing of the data.