Guyane Update

WESSEX EXPLORATION PLC

(AIM: WSX)

Guyane Update

Wessex Exploration PLC ("Wessex" or "the Company") notes the Interim Management Statement of Tullow Oil PLC ("Tullow") made today in respect, inter alia, of progress on the Guyane Maritime Permit, in which Wessex holds an effective 1.25 per cent. interest, which included the following statement:

"Following the basin-opening Zaedyus discovery in French Guiana in September 2011, a drillship has been contracted by the joint venture to commence a comprehensive exploration and appraisal programme in June.

The first well will appraise the discovery made by Zaedyus-1 and explore for deeper objectives, followed by an exploration wildcat well. Planning is also ongoing to acquire two large 3D seismic surveys; a 4,700 sq km Eastern Slope survey and a 620 sq km Cebus survey either side of the Cingulata fan system containing Zaedyus and other mapped turbidite fans."

Shell (45% interest) operates the Guyane Maritime Permit and is partnered by Tullow (27.5%), Total (25%) and Northpet Investments Limited (2.5%), a company owned 50% by Northern Petroleum plc and 50% by Wessex.