NATION

Harold D. Hoopman, 65, who guided Marathon Oil Co. into a $6.2-billion merger with U.S. Steel Corp. three years ago, retired as vice chairman of the parent company and was succeeded by Vice President William E. Swales.

Swales, 60, was also elected to fill Hoopman’s seat on Pittsburgh-based U.S. Steel’s board of directors. He was appointed vice chairman of oil and gas, the position vacated by Hoopman.