Marathon Oil Corporation is engaged in worldwide oil exploration and production of crude oil and natural gas, as well as the domestic refining, marketing and transportation of petroleum products. Marathon Oil Corporation is headquartered in Houston; it is one of the leading oil companies with operations in four continents. Marathon Petroleum Company is a limited-liability company that is wholly owned by Marathon Oil Corporation. The company specializes as a cost-effective and competitive refining, marketing and transportation company that has more than $8 billion in assets. Clarence P. Cazalot Jr. has been the chief executive officer of Marathon Oil for more than 4 years. He has been with the petroleum company for over 6 years. Cazalot Jr. has a bachelor s degree from Louisiana State University. The company s network of operations encompasses more than 20 states in the United States.