The U.S. Court of Appeals for the 6th Circuit has upheld a lower court ruling extending federal preemption to operating subsidiaries of national banks, further solidifying the Office of the Comptroller of the Currency’s claim of exclusive supervisory authority over national banks and their subunits. The 6th Circuit’s Dec. 19 opinion in Wachovia Bank and Wachovia Mortgage Corp. v. Linda Watters strengthened similar appellate opinions that have been rendered in the 2nd and 9th…