Wal-Mart Stores and Tesoro Corp. have reportedly agreed to cease operations of 42 Mirastar fueling stations at Wal-Mart locations across the western United States.

Tesoro will continue operations at 32 remaining fueling stations at Wal-Mart centers, according to Tesoro spokeswoman Sarah Simpson, who was quoted in an online report by the San Antonio Business Journal. Simpson declined to say why Tesoro is closing the stations, stating only that it was a "business decision" for the company.

Wal-Mart and San Antonio-based Tesoro had been developing fueling facilities on Wal-Mart properties since 2000.

Tesoro operates more than 800 retail locations throughout the United States with the exception of Texas. The company saw its net earnings plummet from $443 million during second quarter 2007 to $4 million in second quarter 2008 as unfavorable market conditions continued to afflict the refining industry.

Tesoro is an independent refiner and marketer of petroleum products. The company operates seven refineries in the western United States.