Tesoro Corporation is an independent refiner and marketer of petroleum products. They are a Fortune 100 and a Fortune Global 500 company headquartered in San Antonio, Texas, with 2011 annual revenues of $30 billion, and 5,700 employees.

Tesoro Corporation is an independent refiner and marketer of petroleum products. They are a Fortune 100 and a Fortune Global 500 company headquartered in San Antonio, Texas, with 2011 annual revenues of $30 billion, and 5,700 employees.