Noble Energy Inc., Houston, (NYSE: NBL) has closed its previously announced purchase of United States Exploration Inc., a privately held corporation in Billings, Mo., for $411 million. Noble Energy is proceeding with the integration of United States Exploration's assets into its current operations. The acquisition expands Noble Energy's operations in its core Wattenberg Field in the D-J Basin in Colorado, adding 65,000 acres to Noble's 218,000 net acres in the field. United States Exploration had proved reserves of 248 billion cubic feet equivalent (41% proved developed; 55% gas). United States Exploration's significant shareholders include funds managed by Lime Rock Partners and Greenhill Capital & Co. Petrie Parkman & Co. was advisor to United States Exploration.