Spain Seismic Program with Ciuden commences

LENI GAS & OIL PLC

28 June, 2010

SPAIN SEISMIC PROGRAM COMMENCEMENT WITH CIUDEN

Leni Gas & Oil plc (LGO) the AIM listed international oil and gas exploration, development and production company, today announces the commencement of a seismic survey and investigation program at the Hontomin oilfield location as part of the CIUDEN joint development program.

As announced in March 2009, the Company completed a joint development agreement with the Fundación Ciudad de la Energia (CIUDEN) for the research, testing and implementation of carbon dioxide (CO2) sequestration pilot sites within LGO's Spain acreage.

The seismic program at Hontomin is the first program to be executed under the agreement. The program shall conduct both ultra-sensitive and 3D seismic surveys over an area of approximately 10 sqkm centred on the Hontomin reservoir and shall continue until August 2010. The cost of the survey is approximately 3 million Euro which is wholly funded by CIUDEN.

The terms of the joint development agreement with CIUDEN provide for the full bi-lateral sharing of results and data from all programs executed by the Company and CIUDEN.

The Company anticipates mobilising to Hontomin 2 in July to drill out the well cement plugs and prepare the well for a extended well test programme to assess the production potential of the Hontomin reservoir. All the necessary permits have been granted by the Spanish Government authorities and the majority of the site works have been completed for the programme. Hontomin has mean contingent oil resources of 0.36 mmbo. The oil production from Hontomin 2 will be transported 38km to the Company's central processing and sales facility at Ayoluengo and will provide additional revenues to the Spanish operations.

The results of the extended well test program and CIUDEN seismic survey shall input to the Company's exploitation strategy for Hontomin, for either conducing further appraisal or converting the exploration permit to a production concession.

David Lenigas, Executive Chairman, commented:

"The joint development agreement with CIUDEN has considerable scope for investigating the potential of carbon capture and storage, and related enhanced oil recovery opportunities within our acreage."

"The seismic program on Hontomin is the practical start of this agreement to realise this potential and increase the value of this prospect within our Spain acreage. We look forward to working closely with CIUDEN to maximise the value of Hontomin from this program and our imminent extended well test on Hontomin 2."

Competent Person's Statement:

The information contained in this announcement has been reviewed and approved by Fraser S Pritchard, Executive Director for Leni Gas & Oil Plc (member of the SPE) who has over 20 years relevant experience in the oil industry.

Enquiries:

Leni Gas & Oil plc

David Lenigas, Executive Chairman

Fraser Pritchard, Executive Director

Tel +44 (0) 20 7016 5103

Beaumont Cornish Limited

Roland Cornish / Rosalind Hill Abrahams

Tel +44 (0) 20 7628 3396

Mirabaud Securities Limited

Rory Scott

Tel +44 (0) 20 7878 3360

Pelham PR

Mark Antelme

Tel + 44 (0)20 3178 6242

NOTES TO EDITORS

Leni Gas & Oil Plc is an international oil and gas exploration, development and production company headquartered in London, trading on the London Stock Exchange's AIM index. LGO's strategy is to acquire projects and businesses within the oil and gas sector that contain a development premium which can be unlocked through a combination of financial, commercial, and technical expertise.

LGO operates a low risk portfolio of production expansion assets in the US Gulf of Mexico, Spain, Trinidad and Malta with significant play upside using similar strategies to leverage technologies and proven production enhancement techniques. LGO specifically targets near term production with upside exploitation potential and manages its portfolio to ensure all assets have accelerated incremental reserves and production enhancement programs.

CIUDEN is a Spanish foundation incorporated by the Ministry of Industry, Trade and Tourism, the Ministry of the Environment and the Ministry of Science and Innovation within the Spanish Government. One of CIUDEN's most important technical objectives is research and development (R&D) related to carbon capture and storage (CCS). As part of the R&D effort two pilot plants have been planned, one for carbon capture for which construction has commenced and another where R&D activities to investigate the "life cycle" of underground storage of CO2 will be performed.