US Gulf Coast Acreage Expansion

For Immediate Release

13 July, 2010

LENI GAS & OIL PLC

("LGO" or "The Company")

US GULF COAST ACREAGE EXPANSION

Leni Gas & Oil plc (LGO), the AIM listed international Oil and Gas Production, Development and Exploration Company, today announces an expansion of the acreage position in the US Gulf Coast with the exercise completion of two new developments under terms of the Strategic Alliance Agreement with Byron Energy Pty Ltd ("Byron").

Highlights

·; LGO has acquired 20% direct working interests (16.25% net revenue post royalty) in Ship Shoal block 180 and South Marsh Island block 6 in the shallow offshore US Gulf Coast

·; Ship Shoal 180 contains two prospects with preliminary estimates on best case gross prospective resources in excess of 5 mmboe in the oil case and in excess of 12 bcf in the gas case (2 mmboe)

·; South Marsh Island 6 contains three prospects and one deep potential location with preliminary estimates on best case gross prospective resources in excess of 4 mmboe in the three shallow prospects and in excess of 25 bcf (4.2 mmboe) in the deep prospect

·; LGO now holds interests in five development and production assets in the Gulf Coast. Eugene Island 172 / 183 / 184 (7.25% WI) and Ship Shoal 197 / 201 / 202 (7.25% WI) are currently in production with expansion scheduled in late 2010, South Marsh Island 8 / Eugene Island 133 (7.25% WI) is undergoing drilling planning, and Ship Shoal 180 (20% WI) and South Marsh Island 6 (20% WI) are undergoing geotechnical assessment

Acreage Expansion & Development Plans

LGO has exercised its rights under its Strategic Alliance Agreement with Byron to acquire 20% direct working interests (16.25% net revenue post BOEMRE royalty) in Ship Shoal block 180 and South Marsh Island block 6. These blocks were awarded to Byron by the US BOEMRE in March 2010 as part of lease sale 213. Under terms of the Company's Byron shareholding conversion which was completed at start 2010, LGO and Byron completed a Strategic Alliance Agreement whereby LGO retains the rights to acquire up to a 20% direct working interest in all properties acquired by Byron outwith of the joint venture relationship with Leed Petroleum ("Leed").

Ship Shoal 180 is located east of the Company's existing acreage in Ship Shoal 197 / 201 / 202 held jointly with Leed and Byron and which commenced production in May 2010 at over gross 2000 boepd. Seismic interpretation and review of historical production in block 180 by the Company has identified a significant stratigraphic trapping component with a previous well identifying high quality sands and reservoir sand thickness up to 60 feet.

Ship Shoal 180 contains two prospects with preliminary estimates on gross best case prospective resources in excess of 5 mmboe in the oil case and in excess of 12 bcf in the gas case (2 mmboe). Estimates are in accordance with the SPE Petroleum Resources Management System. The development strategy for Ship Shoal 180 will be two wells drilled from a single surface location on conclusion of further geotechnical works to finalise resources estimates, target locations and drilling economics.

South Marsh Island block 6 is located west of Company's existing acreage in South Marsh Island 8 / Eugene Island 133. South Marsh Island 6 contains three prospects and one deep potential location located near to significant historical production zones and within a large area to trap substantial incremental hydrocarbons. Previous production in the block by Union Oil produced over 24 mmboe from 20 pay zones.

The three prospects have preliminary estimates on best case gross prospective resources in excess of 4 mmboe in the three shallow prospects and in excess of 25 bcf (4.2 mmboe) in the deep prospect. Estimates are in accordance with the SPE Petroleum Resources Management System. The development strategy for South Marsh Island 6 is to reprocess the current 3D seismic dataset to finalise the prospect inventory and resources before identifying development options.

LGO shall fund 20% of the cost of each development on the new properties, expending to date 212,592 US Dollars to acquire the interests. The operator of both properties is Byron.

LGO's other production interests in Eugene Island (7.25%) are currently undergoing well intervention to recommence production in well A7 and return the total platform production to about gross 1000 boepd. Additional development drilling is provisionally planned for end 2010 to access the T1 sands containing the majority of Eugene Island reserves and resources. The undeveloped gross proved reserves in the T1 sands are 4.8 mmboe with probable reserves of 2.8 mmboe (50.50% oil gas) as estimated by Collarini Associates of Texas and previously reported by the Company in April 2010.

The Company does not expect the drilling moratorium and associated appeals in the Gulf of Mexico to apply to its interests as these limitations are only applicable in water depths in excess of 500 feet. All of the Company's Gulf Coast assets are located in less than 200 feet of water.

LGO has engaged Collarini Associates to revise the March 2009 reserves and resources report to include all of the Company's interests in the Gulf Coast. This report is due for completion in mid Q3 2010.

David Lenigas, Executive Chairman, commented:

"The Company is extremely pleased with the considerable expansion of our acreage in the US Gulf Coast with now five assets in various stages of production, development and appraisal."

"The additional assets in Ship Shoal and South Marsh Island are the first in our new joint venture with Byron and have the potential to provide substantial production volumes additive to those current and planned with Leed."

"We anticipate our Gulf Coast investment reaching its potential towards the end of 2010 and 2011 with multiple production volumes onstream."

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 / Henry Lerwill

Tel + 44 (0)20 7337 1500

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.

All reserves and resources definitions are per the Society of Petroleum Engineers Petroleum Resources Management System.

GLOSSARY

bcf = billion standard cubic feet of gas

boe = barrels of oil equivalent calculated on the basis of six thousand cubic feet of gas equals one barrel of oil

bo = barrels of oil

bopd = barrels of oil per day

BOEMRE = Bureau of Ocean Energy Management and Regulation (formerly the Minerals Management Service)

Byron = Byron Energy Pty Ltd / Byron Energy LLC

mm = million

scf = standard cubic feet of gas

scfd = scf per day

SPE PRMS = Society of Petroleum Engineers Petroleum Resources Management System

WI = direct working interest