Shares in oil and gas firm Empyrean Energy received a boost after the announcement that its joint venture partner Hilcorp Energy has been acquired by Marathon Oil, the fourth-largest US-based integrated international energy company.Marathon Oil has reached agreement to buy Hilcorp and its partner's assets in the Eagle Ford Shale trend in Southern Texas for $3.5bn. Hilcorp is currently the operator and joint venture partner (with Empyrean) of the Sugarloaf Project, but will cease to be operator after the acquisition."Hilcorp deserves much praise for the excellent job they have done since taking over operatorship of the Sugarloaf Project and surrounding acreages," said Empyrean's chief executive officer Tom Kelly."Empyrean looks forward to welcoming Marathon as operator and joint venture partner and hope that their vast experience with liquids rich resource plays will result in further value being added."---BC