Wal-Mart is to face a sex-discrimination lawsuit brought by seven current and former female staff that sued the company in June 2001, claiming that Wal-Mart denies women equal pay and opportunities for promotion.

The women want the court to include all current and former female employees at Wal-Mart in the US since December 1998.

If federal Judge Martin Jenkins agrees, the suit could involve some 1.5 million female workers.