An undisclosed privately held company plans to buy the Gulf Coast division of Petrohawk Energy Corp., Houston, (NYSE: HK) for $825 million in cash and a note. The assets include properties on the Texas, Louisiana and Mississippi Gulf coasts that include major discoveries in the Nabors, Colson and Winchester fields. Production is 100 million cubic feet of gas equivalent per day. Proved reserves are 204 billion cubic feet equivalent and proved and probable reserves are 434 billion cubic feet equivalent as of Dec. 31.