Tesoro Corp. agreed to buy Western Refining Inc. for about $4.1 billion in a deal that positions the oil refiner to take advantage of crude production growth in the prolific Permian Basin.
After the purchase, Tesoro will become the fourth-largest independent U.S. refiner with a capacity of more than 1.1 million barrels a day, accounting for about 6 percent of U.S. crude-processing capacity, the companies said in a joint statement Thursday. Western’s assets will expand Tesoro’s network of midstream and retail assets across the Southwest and Mid-Continent regions.