They charge that Wal-Mart has lagged far behind its competitors in its promotion of women and knew of discriminationagainst its female employees but failed to act.
In 2007 Morgan Stanley agreed to settle claims in a class action suit alleging discriminationagainst thousands of female employees in compensation and promotion.
The Supreme Court has in recent years backed limits on class actions, most notably in the 2011 decision that stopped a suit against Wal-Mart involving up to 1.6 million of its female employees who complained of sex discrimination.