Marathon Petroleum Corporation is an American petroleum refining, marketing, and transportation company headquartered in Findlay, Ohio. The company was a wholly owned subsidiary of Marathon Oil until a corporate spin-off in 2011.

BP p.l.c. is a British multinational oil and gas company headquartered in London, England. It is one of the oil and gas "supermajors" and one of the world's largest companies measured by revenues and profits. It is a vertically integrated company operating in all areas of the oil and gas industry, including exploration and extraction, refining, distribution and marketing, power generation, and trading.