Wal-Mart Stores Inc. will urge the U.S. Supreme Court next week to reject the largest class-action sex-discrimination lawsuit in history, brought by female employees who seek billion of dollars.

The top U.S. court hears arguments March 29 in a suit against the world’s largest retailer for allegedly giving women less pay and fewer promotions at 3,400 U.S. stores since late 1998.

Lawyers for the two sides will spar over whether the small group of women who began the lawsuit 10 years ago can represent a huge nationwide class of current and former employees that could total millions of women.

The case has pitted women’s and employees’ rights against business interests, with Robin Conrad of the U.S. Chamber of Commerce calling it “the most important class-action case facing the court in over a decade.”

The case will have far-reaching implications for working women who challenge discrimination, women’s rights advocate Marcia Greenberger of the National Women’s Law Center said.

“The ability of women to be treated fairly in the workplace hangs in the balance,” Greenberger said.

The ruling, expected by late June, could change the legal landscape for workplace class-action lawsuits and affect many cases, including a similar one against Costco Wholesale Corp.

Large class-action lawsuits make it easier for big groups of plaintiffs to sue corporations, and they have yielded huge payouts from tobacco, oil and food companies.

Companies have sought to limit such suits to individual or small groups of plaintiffs.

The Supreme Court, with a conservative majority that has often ruled for businesses, has limited large class-action securities fraud lawsuits and asbestos cases.

If Wal-Mart wins, the huge class would be undone, though the company still could face individual discrimination lawsuits. If the workers win, they would be able to pursue their lawsuit as a group at trial.

Legal experts and financial analysts said Wal-Mart, with more than $400 billion in sales and $16 billion in net income last year, has enough cash to make even a big payout if it loses at trial.

“It would take a seismic ruling against the company to have an impact on the valuation,” said R.J. Hottovy, equity analyst at the Chicago-based Morningstar Inc investment research firm.

The lawsuit has produced testimony that managers held business meetings at Hooters restaurants, attended strip clubs and referred to female employees as “girls,” in what plaintiffs lawyers said was a corporate culture rife with stereotypes demeaning to women.

Wal-Mart, founded in 1962 and based in Bentonville, Arkansas, has denied the allegations and said it has operated under a policy barring discrimination.

The Supreme Court case is Wal-Mart Stores Inc. v. Betty Dukes, No. 10-277.