NEW YORK — Wearing a scanty blue gown with rhinestone clasps, Nicolette Hart explains how she can make up to $2,500 a night with investment bankers and their clients in a Manhattan strip club's private rooms.

She writhes and rubs her nearly naked body against as many as seven men, doing "lap dances" for $400 an hour. (The room costs an additional $200 for the hour.) Hart, who once worked for a venture-capital firm, always asks what brought the men together. They often say they're having a meeting.

"I say, 'You're having a "business meeting" in a "strip club"?' " Hart says in an interview in the dressing room at Rick's Cabaret here.

It's not just strippers who have questions. Some women on Wall Street want to know how it can be fair — or legal — for their managers and male colleagues to exclude them when they fraternize at strip clubs, often with the women's clients. Strip-club clientele is hardly limited to Wall Street. Adult entertainment is enjoyed by men — and some women — in almost every industry in the USA — and it's a tax-deductible business expense allowed by the Internal Revenue Service.

But investment banks and brokerage firms are taking the lead in cracking down on the practice. The National Association of Securities Dealers and the New York Stock Exchange both recently proposed rules that would force companies to adopt business entertainment policies that cap amounts and specify appropriate venues. The move is expected to rule out company-paid or work-related strip-club jaunts at the more than 5,000 brokerage firms in the U.S.

The stock exchange and the NASD acted in large part because of lawsuits brought by women employees.

The women who have sued say strip clubs are emblematic of a larger problem on Wall Street: a macho culture that leaves them behind in all areas. "There are two levels of discrimination: the frat-house environment in the office and the deeply embedded practices that are just starting to be uncovered, like the distribution of accounts, business leads and promotions," says Hydie Sumner, a financial consultant who was awarded $2.2 million in 2004 after suing Merrill Lynch for gender discrimination. "When 'business activities' involve the strip club, golf course or hunting ranches, discrimination is often perpetuated as those in power support and advance those with like minds and tastes."

Ultimately, some believe, other industries will be affected. "This is going to have a trickle-down effect," says Aliza Herzberg, a New York employment lawyer who represents many manufacturing and small-business clients. "Companies will try to make taking clients to strip clubs, which is very common, a thing of the past — just like the three-martini lunch."

It was a Fidelity Investments trader's 2003 bachelor party, paid for by brokerage firms including Jeffries, that prompted NASD to consider tightening its rules. The party allegedly included dwarf-tossing and paid female escorts, according to news accounts and investigators.

"We're not happy that (business entertaining) seems to have been an area where firms were not paying sufficient attention," says NASD Vice Chairman Mary Schapiro. "I thought sensitivity to issues like this would have been greater than it was."

NYSE executive vice president Grace Vogel says the goal is to ban entertainment that's inappropriate or excessive. Final versions of the rules, likely in weeks, must be approved by the Securities and Exchange Commission before taking effect. Brokerage firms that don't enact or enforce business entertainment policies could face actions ranging from censure to expulsion.

Many companies now have policies that restrict any behavior that excludes certain employees, even if they don't mention strip clubs, says Las Vegas employment lawyer Barry Kellman.

"Financial services has taken the biggest hit (from lawsuits), but the more buttoned-up industries would have greater concern about this than, for example, the entertainment industry," Kellman says.

Earlier this month, the Manhattan strip club Scores settled a lawsuit over a contested $241,000 bill racked up by the former CEO of St. Louis information technology company Savvis. Robert McCormick resigned amid an investigation into the bill, which was charged to his corporate American Express card. Several sexual harassment lawsuits have been filed in recent weeks by women who say male co-workers at freight logistics company C.H. Robinson frequented strip clubs and openly discussed strippers in the office.

Attorney Rohit Sabharwal, a Rick's regular, says he often takes clients of his small law firm with him and such entertaining was common when he was at a large firm, too. "Nobody really objects," Sabharwal says. "I think it's a lot more civilized in the law profession. I don't think women have a problem succeeding in law firms."

But back on Wall Street, Vogel says the rulemakers had "uncanny timing":

In the fall, Morgan Stanley fired three salesmen and a researcher who took clients to a strip club. The company instituted a no-strip-club policy in October 2002, two years before it paid $54 million to settle a sex discrimination lawsuit. The suit was brought by the Equal Employment Opportunity Commission and a former institutional equities saleswoman who said she was excluded from client outings to strip clubs and other places.

Six female employees filed a sex discrimination class-action complaint in federal district court against German investment bank Dresdner Kleinwort Wasserstein in January. Jyoti Ruta, a director in the institutional equities division here, says she was excluded from a trip to a strip club and from other client events.

Last April, a jury found in Laura Zubulake's favor in a sex discrimination and retaliation lawsuit against UBS and awarded her $29 million. In October, the parties settled the lawsuit privately.

Several financial companies say the proposed rules are too burdensome. John Goodwin of Albuquerque-based Goodwin Browning & Luna Securities, complained to NASD that it is "legislating morality."

But female plaintiffs and their lawyers say business entertaining can be as important as what goes on in the office.