William E Greehey is Chairman of NuStar Energy, a Fortune 500 energy company. He was formerly Chairman, president, and CEO of Valero Energy, another Fortune 500 energy company
The company was established in 2007 after separating from Valero. The company operates 9,113 miles of pipeline and 85 terminal facilities across six countries allowing for the storage of almost 80 million barrels of oil making NuStar the second largest independent liquids terminal operator in the world. In 2007, the company announced that it would purchase CITGO Asphalt Refining Co. for $450 million. This move made NuStar the largest asphalt refiner on the East coast.