Bill Klessewill step down as CEO of Valero Energy Corp. May 1, but will remain a director and chairman of the board, the San Antonio-based company said. Klesse, who has spent his entire 45-year career with Valero and its predecessor companies, became CEO in 2005 and was named chairman of the board in 2007. Joe Gorder, who was elected president and COO in 2012, will become CEO effective May 1. He was immediately elected to the board of directors. During his 27 years with Valero, Gorder has held positions including executive vice president, chief commercial officer and president of Valero Europe; executive vice president-Marketing and Supply; and senior vice president for Corporate Development and Strategic Planning.