AIM-listed oil & gas exploration group Lekoil Nigeria announced its subsidiary Lekoil and Gas has agreed to buy a 40 per cent stake in the Otakikpo Marginal Field.The West-Africa focused group will buy the stake from Green Energy International which holds 90% of economic interests in Lekoil. The firm predicts production at Otakikpo could begin within 12-18 months. The field lies in a swamp location in oil mining lease, offshore Nigeria which is held by Nigerian National Petroleum Corporation. The company has entered into a farm-in agreement with the Farmor, and is expected to pay a signature bonus of £7m which is contingent on production and an additional production bonus of $4m.The firm announced in March it had started a 3D seismic programme on the OPL 310 offshore Nigeria. The programme will cover an area of about 1,505km sq representing approximately 80% of the acreage within OPL 310. Chief Executive Officer Lekan Akinyanmi said: "Acquiring this interest in Otakikpo is a very attractive proposition, economically and operationally for Lekoil. "It brings access to near term production - in line with our growth strategy, cash flow to fund activity on our other assets and upside potential to be proved up from 3D seismic and appraisal drilling. As the Technical and Financial Partner we will be able to showcase the technical ability within the company to bring assets into production."As of 13:23 the share price had had dropped by 4.5% to 65.5p.WS