Valero Buying Ultramar for $4B

Valero Energy Corp. is buying Texas rival Ultramar Diamond Shamrock Corp. for about $4 billion in cash and stock in a deal that will make Valero the second-largest U.S. refiner of petroleum products.

The acquisition, announced Monday, was approved by both companies' boards over the weekend. It still must be approved by both companies' shareholders and regulators.

The new organization will have $32 billion in annual revenue, more than $10 billion in assets, 23,000 employees in the United States and Canada and 13 refineries. Valero will also be one of the nation's largest retailers with more than 5,000 retail outlets in the U.S. and Canada.