Thalassa (di) Regulatory News (THAL)

31 May 2011

Thalassa Holdings Ltd

("Thalassa" or the "Company")

Valhall Contract Update

Successful Completion of 13th LoFS Survey

The Company's operating partner, WGP Group, released the following press statement in respect of the contract on the Valhall field:-

"WGP completes 13th LoFS Survey on Valhall Field

M/V Stril Myster, Valhall, May 2011

WGP are proud to announce the successful completion of the thirteenth Life of Field Seismic (LoFS) survey over the Valhall field in the North Sea.

BP Norge AS, and operating partner Hess Norge AS, have contracted WGP to provide the precisely positioned source sub-arrays necessary to maintain the high level of repeatability required for an effective Permanent Reservoir Monitoring (PRM) project. With the trenching of 120km of Ocean Bottom Cable (OBC), Valhall LoFS began in 2003 with an average of 2 surveys performed per year.

WGP installed Thalassa Energy Services' containerised seismic source system onto the PSV Stril Myster during a 6 day mobilisation period in Stavanger. Thalassa's source system is the same design as used on all of the LoFS surveys since the project's inception and thus affords the required level of source repeatability.

The Valhall LoFS 14 survey is planned for Q3 2011."

Duncan Soukup, Chairman of Thalassa, and James Pryor, WGP's Business Development Manager, commented: "As proven in past Valhall LoFS surveys and other PRM projects for which WGP have used a Portable Modular Source System (PMSS™), this technology affords rapid conversion of an available PSV, familiar with the particular oilfield's operations, into a working seismic source vessel. Combining WGP's comprehensive operational experience with Thalassa's industry leading source systems makes both good sense and presents great value for our clients."

Contact:

Duncan Soukup, Chairman Tel: + 33 (0)6 78 63 26 89

Thalassa Holdings Ltd

Antony Legge/Oliver Rigby Tel: + 44 (0)20 7776 6550

Daniel Stewart & Company plc

Notes to Editor:

Thalassa Holdings Ltd, incorporated and registered in the BVI in 2007 and listed on AIM in July 2008, is a holding company with a focus on Marine Seismic operations.