Newfield Exploration Co. and Hess Corp. plan to start drilling in 2010 on a joint exploration venture to exploit gas in Devonian Marcellus shale in NE Pennsylvania. Newfield will operate the 50-50 venture, which covers as much as 140,000 gross acres in Susquehanna and Wayne counties. The two companies expect to finalize agreements in coming weeks for the Appalachian basin program.