NEW YORK (AP) _ Home Depot, one of the nation's largest retailers, has built a ``glass ceiling'' to keep women from being hired or promoted _ even to the level of salesperson, according to a federal lawsuit filed Monday.

``Women at the Home Depot have been treated shabbily,'' said William Brown, attorney for four ex-employees from Louisiana who have sued the building materials chain.

On Monday, the Equal Employment Opportunity Commission announced it would join a class-action case first filed by the four women in 1995 in New Orleans federal court.

``In too many instances, women at Home Depot were hired only for jobs such as cashier's positions, but not others,'' said C. Gregory Stewart, general counsel for the federal agency, speaking at the EEOC's New York offices.

``While Home Depot has a glass ceiling, it traps its female employees in what amounts to a glass basement, with glass walls,'' said Stewart.

The EEOC is suing on behalf of about 22,000 women working in 310 Home Depot stores in the eastern United States _ in what Stewart called a ``hostile working environment.''

In Atlanta, the company issued a statement saying it was ``puzzled and outraged'' by the EEOC's decision to intervene.

``The Home Depot will vigorously oppose intervention, and is confident that it can demonstrate that intervention is not only futile, but a waste of government resources,'' said company vice president Larry Smith. ``The EEOC only chose to listen to one-side of the story. There is no way they could have gotten a balanced and accurate picture of the case.''

Two other sex-discrimination lawsuits have been filed against the retailer in California and New Jersey, involving employees of the huge warehouse-like stores that offer home improvement supplies at prices often lower than smaller retailers.

One of the plaintiffs in the EEOC case, Carol Lee Griffin, described working at a Home Depot in New Orleans from 1991 to 1994.

``I always felt like I was fighting a battle,'' said the kitchen designer who was hired to advise customers at the store.

She said when helping customers, she was ``constantly called back'' to her work station by male colleagues. And the 59-year-old woman said that when she asked the store manager why he never spoke to her as a professional, he said, ``But I think of you as my mother.''

Finally she was fired after being told she had taken an unauthorized break in the store's ``general room'' when, in fact, she said she was there studying a customer's project.

``I was never given an opportunity,'' she said.

The three other plaintiffs in the case, who also worked for Home Depot in Louisiana, included a woman who was ``steered into a cashier's position'' though she had applied for a sales job, said James Lee, an attorney for the EEOC's New York district office.

In California, a class-action suit is pending on behalf of all Home Depot female employees working in 10 Western states, and a woman who worked at a Home Depot in New Jersey is awaiting resolution of her suit against the company.