(ShareCast News) - UK Oil & Gas Investments on Friday announced it has bought a further interest in the Horse Hill-1 oil discovery.The group bought a 3.9% stake of Flowermay Limited in onshore Weald Basin licences PEDL137 and PEDL246 for £1m, bringing its total interest to 31.2%. UK Oil & Gas will receive a 3.9% beneficial interest in the licences though the acquisition of Flowermay's remaining 6% shareholding in Horse Hill Developments.The licences cover 55 square miles north of Gatwick Airport and contain the Horse Hill-1, Portland and Kimmeridge Limestone oil discoveries. The Horse Hill-1 flow tested at a "significant 'North Sea-like'" commercial aggregate stable dry oil rate of 1,688 barrels of oil per day, according to a report on 21 March.Regulatory permissions have been requested for significant long-term production testing and an appraisal programme of Kimmeridge Limestones and Portland oil-bearing reservoirs.