Thalassa (di) Regulatory News (THAL)

29 June 2012

THALASSA HOLDINGS LTD

(Reuters: THAL.L, Bloomberg: THAL.LN)

("Thalassa" or the "Company")

TOTAL VOTING RIGHTS

For the purposes of the Financial Services Authority's Disclosure and Transparency rules, the Company announces that as at 29 June 2012 the total number of ordinary shares of USD0.01 in issue is 11,192,522 of which 1,462,000 are held in Treasury.

The figure of 9,730,522 ordinary shares may therefore be used by shareholders in the Company as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change in their interest in, the share capital of the Company under the FSA's Disclosure and Transparency Rules.

For further information please contact:

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

Thalassa Holdings Ltd

Antony Legge/Tessa Smith Tel: + 44 (0) 20 7776 6550

Daniel Stewart & Company Plc

www.thalassaholdingsltd.com

Notes to Editor:

Thalassa Holdings Ltd, incorporated and registered in the BVI and quoted on AIM, is a holding company with a focus on marine seismic operations. The corporate strategy for the Group is "Exploration and Beyond". "Exploration" is focused on activity in frontier and challenging locations, whilst "Beyond" focuses on production activity by looking to secure opportunities in the permanent reservoir monitoring market. Thus activity and focus will be dominated by projects in remote and challenging frontier locations, coupled with lower risk projects in mature producing regions.

Alongside the technical expertise and consultancy in marine seismic operations provided through its subsidiary, WGP, the Group owns and operates two portable modular source systems (PMSS™). The PMSS™ generates a seismic source for use in seismic acquisition for use in petroleum exploration and production. The equipment is temporarily installed on the back of a platform supply vessel for the purposes of acquiring data.