SALT LAKE CITY (AP) — Billionaire Robert Earl Holding, whose business empire included ownership of Sinclair Oil and two world-class ski resorts in the West, has died at the age of 86.  Sinclair Oil issued a statement saying Holding died Friday.  According to Forbes, the Utah native's net worth of $3.2 billion made him the 423rd wealthiest person in the world at the time of his death.  In 1952, he became manager of the Little America truck stop near Green River, Wyo. He acquired the Mobil refinery in Casper, Wyo., in 1968 and Sinclair Oil in 1976.  He later purchased the Sun Valley Resort in Idaho and Snowbasin Resort in Utah. He also was a member of the Salt Lake Organizing Committee board that lured the 2002 Winter Games to Salt Lake City.