NEW YORK ( TheStreet) -- Wal-Mart ( WMT - Get Report)is entwined it what could be the largest sexual discrimination class-action lawsuit in U.S. history.

A U.S. appeals court ruled on Monday that a lawsuit brought by female Wal-Mart employees can go to trial, which could result in billions of dollars in losses for the discount giant.

The workers are alleging that Wal-Mart pays women less than men for the same jobs and that female employees receive fewer promotions.

The suit was first filed in a federal court in San Francisco in 2001. Since then Wal-Mart has lost two rulings in trial court and another in the appeals court in 2007.

-- Reported by Jeanine Poggi in New York.

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