WASHINGTON — The Supreme Court has agreed to hear an appeal by Walmart in a class-action sex discrimination case against the giant discounter.

The Supreme Court has agreed to hear an appeal by Walmart in a class-action sex discrimination case against the giant discounter.

At issue is whether the claims by so many individual employees can be combined into one giant class-action suit. The suit against Walmart was filed in 2001 by six women on behalf of all current and former Walmart employees who are women, numbering in the thousands. The plaintiffs allege that they were denied equal access to pay and promotions due to their gender. They are seeking back pay, punitive damages and changes in the way Walmart makes its pay and promotion ­decisions.

Walmart contends that the group of women the suit claims to represent is too large and diverse to be considered a single class for the purposes of such a lawsuit. Walmart’s female employees worked for different managers in 3,400 different stores, in 170 different job classifications, and therefore do not have enough in common to have their claims decided in a single action.

Lawyers for the plaintiffs argue that the class is so large because Walmart is, and because the retailer runs its employment practices in a consistent and centralized way.

An 11-member panel of the United States Court of Appeals agreed (although not unanimously) with the plaintiff’s argument back in April, ruling 6 to 5 that the class-action lawsuit could go forward.

It is that decision, rather than the issue of whether the alleged discrimination actually occurred, that the Supreme Court will review.

"We are pleased that the Supreme Court has granted review in this important case," Walmart said in a statement. "The current confusion in class-action law is harmful for everyone — employers, employees, businesses of all types and sizes, and the civil justice system. These are exceedingly important issues that reach far beyond this particular case."

Experts believe the Supreme Court’s decision on the case could result in the establishment of a new standard for class-action lawsuits that would affect cases involving antitrust, securities, product liability and other claims.

Walmart’s petition for appeal was supported by a number of other large companies, including Bank of America Corp., General Electric Co. and Microsoft Corp.

The plaintiff’s bid to deny the appeal was supported by the Equal Employment Opportunity Commission.