Citing the U.S. Supreme Court's recent Walmart ruling, a federal appeals court set aside - but did not dismiss - a class-action suit by more than 700 women who accused discount retailer Costco of using an "old-boys' network" to bypass them for promotions.

A federal judge in San Francisco ruled in 2007 that the women had presented enough evidence of a "common culture" at Costco to proceed with a single nationwide suit against the company, rather than file individual claims.

The Ninth U.S. Circuit Court of Appeals overturned that decision Friday, relying in part on the Supreme Court's ruling in June dismissing a class action against Walmart by as many as 1.5 million female employees. The high court said the women had failed to show a company-wide policy that allegedly led to gender-based disparities in pay and promotions.

Likewise, the appeals court said, the Costco plaintiffs have not yet shown that they have enough in common to justify a class action.

The court said opposing expert witnesses disagreed about a central issue - whether the company promoted women less often than men in all regions or only a few - and said U.S. District Judge Marilyn Hall Patel should have resolved the dispute before letting the case proceed.