Is Marathon Oil Exiting the Marcellus Shale? Energy Companies | Marathon Oil | Triana Energy September 27, 2012September 27, 2012 Rumors are leaking that Marathon Oil Corp. has put 80,000 Marcellus Shale acres in West Virginia and Pennsylvania up for sale in an effort to trim back on “non-core” assets. Here’s what’s being reported: Please Login to view this content. (Not a member? Join Today!) Related