MIAMI (AP) — Three female Walmart Stores Inc. employees have filed a lawsuit in South Florida claiming the retail giant discriminates against women in areas such as wages and promotion opportunities

The potential class-action lawsuit filed Thursday in federal court is at least the fourth in various parts of the country. Others have recently been filed in Tennessee, Texas and California.

The company insists it has strong policies against any form of discrimination.

The regional lawsuits follow a 2011 U.S. Supreme Court decision that tossed out a national gender bias lawsuit seeking to represent some 1.6 million female Walmart workers. The high court said the allegations were too varied to show a national pattern of discrimination.

Walmart has also said the claims of a few workers are not representative of all employees.