Supreme Court sides with Wal-Mart in sex discrimination lawsuit.

The U.S. Supreme Court, in a ruling that may mean new limits on class-action suits, rejected an effort to sue Wal-Mart Stores Inc. for discrimination on behalf of potentially a million female workers.

The justices said the lawyers pressing the case failed to point to a common corporate policy that led to gender discrimination against workers at thousands of Wal-Mart and Sam’s Club stores across the country. The court ruled unanimously on some aspects of the case and divided on others.

The case was one of the most closely watched Supreme Court business disputes in years, in part because the justices hadn’t looked at the standards for certifying a class-action suit in 12 years. Billions of dollars were at stake for Wal-Mart, the world’s largest private employer.

Filed in 2001, the suit aimed to cover every woman who worked at the retailer’s Wal-Mart and Sam’s Club’s stores at any point since December 1998, including those not hired until years after the suit was filed.

The women pressing the suit claim they and colleagues across the country were victimized by Wal-Mart’s practice of letting local managers make subjective decisions about pay and promotions.

A federal appeals court had let the suit go forward on behalf of women who were working at Wal-Mart at the time the suit was filed.

Units of Cigna Corp., Goldman Sachs Group Inc., Bayer AG, Toshiba Corp., Publicis Group SA, Deere & Co. and Costco Wholesale Corp. all face gender discrimination complaints that seek class action status. More than 20 companies supported Wal- Mart at the Supreme Court, including Intel Corp., Altria Group Inc., Bank of America Corp., Microsoft Corp. and General Electric Co.

The case is Wal-Mart Stores v. Dukes, 10-277.