Valero Energy Corporation specializes in refining and retailing operations. The company engages in wholesale marketing, transportation activities, and product supply and distribution. Its products include reformulated gasoline, diesel fuel and oxygenates. Valero Energy Corporation also provides conventional gasoline, distillates, jet fuel, asphalt, petrochemicals and lubricants. The company maintains nearly 20 refineries in the United States, Canada and Aruba. It has more than 4,700 retail sites branded as Valero, Diamond Shamrock, Ultramar, Beacon and Total. Valero Energy s company-operated convenience stores sell snacks, candy, beer, cigarettes and coffee. William R. Klesse has been the chief executive officer of Valero Energy for more than one year. He has been with the petroleum company for over 37 years. Klesse earned a BS degree from the University of Dayton, and a MBA from Texas A&M. The company was established in 1955 and is headquartered in San Antonio.