Horizon Offshore, Inc. announced the election of John T. Mills to its board of directors. John T. Mills is senior vice president and chief financial officer of Marathon Oil Corporation. Mills joined Marathon Oil Company in 1976 as a tax specialist. He became chief tax counsel in 1984. In 1986, he became director of taxes and energy for USX Corporation. He was appointed vice president of taxes for USX in 1987. In September 1998, Mr. Mills was appointed senior vice president of finance and administration at Marathon Oil Company. Prior to joining Marathon, Mr. Mills was employed by Coopers and Lybrand for three years. Mr. Mills earned a bachelor's degree in economics from Ohio University in 1969 and a law degree from Ohio State University in 1973.