Premcor Inc., the nation's sixth largest independent refiner, said yesterday it has retained investment bankers Credit Suisse First Boston to assist it in a review of "alternatives to maximize the value of the company." Other published reports this morning indicated the company's majority owner, the Blackstone Group, L.P., is seeking a merger, sale or joint venture for the struggling refiner.

Tosco Corp., in an effort to boost lackluster retail gasoline profits, has begun raising wholesale gasoline prices in Southern California and Arizona, two markets where it has significant market share, The Wall Street Journal reported yesterday.

Alon USA said it plans to acquire Southwest Convenience Stores, LLC and its 174 licensed 7-Eleven convenience stores in West Texas and New Mexico for an undisclosed sum. The deal is expected to close next month.