(ShareCast News) - Westmount Energy's shares are up 2% as it acquired a stake in Eco (Atlantic) Oil & Gas Ltd (EOG) to obtain a low-cost exposure to the Orinduik block in the Guyana basin.The company subscribed for about 3.13m shares Eco at 16p each, funded from Westmount's existing resources and a loan of £250,000 from chairman Gerard Walsh.EOG is a Canadian oil and gas exploration company with interests in the 1800 sq km Orinduik offshore block in Guyana and four offshore petroleum licenses, covering more than 32,000 sq km in the Walvis and Luederitz Basins in Namibia.Walsh said the motive for the investment in EOG was to offer Westmount shareholders a low entry cost for exposure to the Orinduik block."The Orinduik block is operated by Tullow Oil Plc and is adjacent to the Stabroek Block operated by Exxon Mobil that contains the world-class Liza discovery," he said.The Liza discovery was estimated by Exxon to have recoverable resources of about 1.4bn barrels of oil equivalent, together with the recently announced Payara discovery.At about 13:20 GMT, shares in AIM-listed Westmount were up 2% to 6.38p each.