The San Francisco Chronicle is reporting that Chevron has agreed to purchase additional Marcellus assets in Pennsylvania from Chief Oil & Gas LLC and Tug Hill Inc. "The transaction is expected to close by the end of June and will give the company access to about 5 trillion cubic feet of gas in the area, the company said. In February, Chevron completed its $3.58 billion purchase of Atlas Energy Inc., a Moon Township, Pa., owner of 622,000 acres in the Marcellus Shale."