The biggest sexual discrimination case in US history advanced against Wal-Mart last week when a top court ruled that more than 1.6 million women could join a class-action law suit.
Legal experts have estimated that Wal-Mart's liability in the case could run as high as $11bn (£5.5bn) and involve as many as two million women who have worked for the retail giant since 1998.
The suit claims female employees were discriminated against in pay and bypassed for promotion, something strongly denied by the company.
US district judge Martin Jenkins ruled that lawyers for the women had enough anecdotal evidence to warrant a class-action trial. He argued that it was "impractical" to have individual hearings for each plaintiff, and planned to use a statistical formula to compensate each of the women.
Wal-Mart had argued that granting the lawsuit class-action status was inappropriate because its 3,400 US stores operated as individual businesses, and issues of pay and promotion were decided on a local basis.
But David Nassar, executive director of campaign group Wal-Mart Watch, said: "Despite Wal-Mart's efforts to stonewall, delay and obfuscate, today's judgment brings us miles closer to justice and vindication for two million victims of the company's immoral and illegal gender discrimination."