Teekay Tankers owns and manages a fleet of about 30 tankers, which it charters to such customers as SPT (Skaugen PetroTrans) and Valero for use in seaborne transportation of crude oil. The company generates revenue by selling both short-term voyage charters and longer-term time charters. Teekay Corporation, a leading marine transporter of petroleum products, retains a 42% interest in Teekay Tankers, which it spun off in 2007. A Teekay Corporation subsidiary manages the Teekay Tankers fleet. Teekay Tankers bought its initial fleet of tankers from its parent with the proceeds of its 2007 IPO.