Feb 28 - Overview -- U.S.-based Murphy Oil Corp. has sold its Superior, Wisc. and Meraux, La. Refineries and is evaluating the potential spin-off or sale of its U.K. refinery and U.K. and U.S. retail businesses. -- We are affirming our ratings on Murphy Oil Corp. and removing them from CreditWatch. -- The outlook is stable, reflecting our expectation that Murphy will maintain adjusted debt leverage of about 1x or less and funds from operations (FFO) to adjusted debt