SLE.L Regulatory News (SLE)

San Leon Energy Plc

("San Leon" or the "Company")

Seismic survey - Atlantic Margin, West coast of Ireland

San Leon is pleased to announce that it has awarded PGS Ventures AS ("PGS"), a subsidiary of Petroleum Geo-Services ASA Group, a contract to carry out a 300 sq. kms. seismic survey across the Slyne Basin in the Atlantic Margin, offshore west coast of Ireland. The license for exploration in the Slyne Basin was acquired by San Leon following the takeover of Island Oil & Gas in May 2010.

The ultra-high capacity seismic vessel M/V Ramform Vanguard, will shortly be on route to Ireland with the survey scheduled to commence later this month and be completed by the end of August.

The interests in the Slyne Basin are San Leon 50% and Lundin 50%. As detailed on 18 September 2009 San Leon entered into a seismic services agreement with PGS, who will provide up to a $50m facility for seismic services.

Oisín Fanning, Chairman of San Leon commented

"We are delighted to have awarded this contract to PGS who we know well and are working with across our asset base. The San Leon team have mobilised this significant seismic programme rapidly and it is the first work that we are carrying out on these assets; which we only acquired in May through the acquisition of Island Oil and Gas. The Atlantic margin is an exciting area for us and one that John Buggenhagen, our Vice President of Exploration, considers to have the potential that the North Sea had some forty years ago."

7 July 2010

For further information contact:

San Leon Energy Plc Tel: + 353 1291 6292

Oisin Fanning, Chairman

Philip Thompson, Chief Executive Officer

Arbuthnot Securities Tel: +44 (0) 20 7012 2000

Nick Tulloch

Ben Wells

College Hill Associates Tel: +44 (0) 207 457 2020

Nick Elwes

Qualified person

John Buggenhagen has over 15 years experience in the oil & gas industry. He has a Ph.D. and M.Sc. in Geophysics from the University of Wyoming and a B.Sc. in Geophysics from the University of Arizona. He is currently the Vice President of Exploration for the San Leon Energy group and based in San Leon Energy's Warsaw office in Poland.