BP said the Federal Trade Commission cleared the sale of its refinery in Carson, Calif., and retail network in the region to Tesoro for about $2.5 billion.
"With FTC clearance, we have taken a significant step closer to completion of this sale and to the strategic refocusing of our U.S. fuels portfolio," BP Refining Chief Executive Officer Iain Conn said in a statement.
The Carson refinery, which started operations in the 1930s, can process about 266,000 barrels of oil per day. The sale includes about 800 retail fueling stations and associated storage assets.
Tesoro, which has headquarters in Texas, owns and operates refineries in California that can process 263,000 bpd. Company President Greg Goff said FTC approval cleared the way for the "transformational acquisition."
"This transaction is a unique opportunity for Tesoro to combine the best aspects of two West Coast refining, marketing and logistics businesses resulting in a more efficient world-scale integrated refining, marketing and logistics system," he said in a statement.
BP has sold some larger assets as its pays off some of the debt associated from the oil spill in the Gulf of Mexico in 2010.