Tesoro Corporation, known briefly as Andeavor, was a Fortune 100[4] and a Fortune Global 500 company headquartered in San Antonio, Texas, with 2017 annual revenues of $35 billion, and over 14,000 employees worldwide. Based on 2017 revenue, the company ranked No. 90 in the 2018 Fortune 500 list of the largest United States corporations by total revenue.[5]
Tesoro was an independent refiner and marketer of petroleum products, operating ten refineries in the Western United States with a combined rated crude oil capacity of approximately 1200000 oilbbl per day. Tesoro's retail-marketing system included approx. 3,000 branded retail gas stations, of which more than 595 were company-operated under its own Tesoro brandname, as well as Shell, ExxonMobil, ARCO, and USA Gasoline brands.
Tesoro, known at the time as Andeavor, was acquired by Marathon Petroleum