Bloomberg | Marathon Petroleum to Buy Andeavor in Biggest Oil Refining Deal Bloomberg Marathon is focused in the Midwest and Gulf Coast, while Andeavor concentrates on the western U.S., including refineries and pipelines it acquired in last year's merger with Western Refining Inc. The combination, which will use the name Marathon, would ... Big Oil deal creates largest American refinery Texas Billionaire Cashes In As Marathon Grabs Andeavor To Become Biggest US Oil Refiner Ohio-based Marathon Petroleum to buy Andeavor in $23.3 billion oil-refining deal |