Marathon Oil will plough ahead as a purely upstream company from 30 June, when the split comes into effect.
The company will operate and report through three segments — exploration and production, oil sands mining, and integrated gas.
It will continue to trade on the New York Stock Exchange under its ticker symbol MRO and will remain based in Houston.
The downstream business, Marathon Petroleum, will be based in Findlay, Ohio, and expects to be the fifth largest US refiner.
It
