The lawsuit, filed on Monday, accused Dresdner Kleinwort Wasserstein Securities LLC of letting inappropriate and offensive behaviour flourish at the US wing of Dresdner Bank, which provides a full range of capital markets and advisory services for clients.
It is owned by Allianz AG.
It also said the company prevents advancement and fair treatment, and maintains a corporate culture that excludes and demeans women.
The lawsuit in US District Court in Manhattan offered a slew of statistics to back up the claims - noting, for instance, that only 1.6% of women in the company's Capital Markets Division are managing directors.
In contrast, 15% of men employed by that division hold that position.
The lawsuit said: "Although we live in 2006, the 'glass ceiling' is alive and well at this German investment bank, where women are treated as second-class citizens with respect to all of the terms and conditions of their employment.
"This class action seeks to put an end to these intolerable and discriminatory practices."
In a statement, the company said its policy is to decline comment on pending litigation but that it "intends to vigorously defend this matter."
The lawsuit says there is a lack of
women in senior bank positions
It said the company "fully complies with all applicable employment-related laws and is confident that any claims to the contrary are without merit."
Six named plaintiffs said they were seeking an end to the unlawful denial of promotions as well as compensation equal to male employees and equality in other conditions of employment.
The lawsuit said the lack of women in senior positions at the company contributed to a "pervasive discriminatory culture".
Jyoti Ruta, one of the plaintiff's, alleged that she was pressured by a supervisor and a colleague to leave a dinner celebrating the closing of a major deal, so that male employees and clients could go to a strip club.
Katherine Smith, another plaintiff, said that she had been subjected to vulgar comments by her boss. When she objected, the man laughed, the suit said.
Two months later, during a work lunch to welcome a new hire, the man referred to Smith as "the Pamela Anderson of trading," the lawsuit said.
Plaintiff Kathleen Treglia said salesmen on her desk openly commented that they chose female junior hires based on appearance because they wanted "eye candy" in the office, the lawsuit said.
Dresdner Kleinwort Wasserstein
Securities is owned by Allianz AG
It said Treglia also heard male colleagues recount their strip club experiences.
Plaintiff Maria Rubashkina said she was aware of a male managing director in the Corporate Finance and Origination department who routinely brought prostitutes to the office during lunch hour.
The plaintiffs alleged that the company condoned intimate relationships between its top executives and their female subordinates and cited the example of a married former chief executive officer who openly dated his personal assistant, with whom he had a child.
The lawsuit said that, in addition to barriers to advancement to the highest executive level - managing director - there also were barriers at the lower levels.
"The 'glass ceiling' is alive and well at this German investment bank, where women are treated as second-class citizens"
It said the statistics reveal "a telling picture ... in which women are subjected to the lowest pay and rank."
As of May 2005, women comprised only 99, or fewer than 15%, of 775 positions as directors, the second-highest executive level in the company's Capital Markets Division, the lawsuit said.
In addition, about 300, or 60%, of the 500 women in the department were associates, while only 379, or 22%, of the 1700 male employees in the division were associates, the lawsuit said.