The lawsuit filed in Manhattan federal court on Wednesday is the latest in a history of allegations of gender discrimination in the financial services industry, including a complaint one month ago against Wall Street's most profitable bank, Goldman Sachs Group Inc .
Goldman said the lawsuit was without merit and Citigroup said on Wednesday that 13 top positions were occupied by women, from chief executive officer of Citi Financial North America, to head of North America markets to general counsel of consumer banking.
"These cases haven't gone away. You still see them with some degree of frequency," said Professor Christine Chung of Albany Law School in Albany, New York.
She said that, while not all of the gender bias allegations end up in federal court, firms defend themselves vigorously and "have made advances and do point to them."
Wednesday's lawsuit said five of the women were among thousands laid off in November 2008 amid the banking crisis, while "in most circumstances Citigroup retained less qualified male employees." The sixth, who still works at Citigroup, said she was subjected to comments she considered offensive to women and that she was demoted after returning from maternity leave.
It said Citigroup's Senior Leadership Committee is dominated by men -- 39 men to five women -- and all 19 members of the Executive Committee are men.
"Given this disparity in the most senior level positions, it is not surprising to find that the 'boys club' filters down through the management ranks to affect all senior and junior level professional positions," the lawsuit said.
The women's lawyer, Douglas Wigdor of Thompson Wigdor and Gilly LLP, said they filed an action with the U.S. Equal Employment Opportunity Commission, which granted the right to sue.
A Citigroup spokeswoman, Danielle Romero-Apsilos, said in a statement the bank had not yet been served with the complaint.
"We will respond to the specifics when we have a chance to review the allegations," she said in an emailed statement. "Citi has a long-standing commitment to equal employment practices and to provide a professional and respectful workplace free of unlawful discrimination."
The women are seeking class action status for women currently and formerly employed at Citigroup at levels including managing director, director, vice president, assistant vice president, associate and analyst, between February 2006 and the present.
They are also seeking unspecified monetary damages under United States and New York State civil rights and human rights laws.
Plaintiffs Amy Bartoletti and Brittany Sharpton of New York City, Chia Siu of Long Island City, New York, Nadine Mentor of Orlando, Florida, and Lisa Conley of Chicago were employed in the Public Finance Department within Citigroup's Municipal Services Division.
The sixth plaintiff, Dorly Hazan-Amir of Hoboken, New Jersey, is currently employed by Citigroup in the Asset Finance Group, according to the court document.
The case is Amy Bartoletti v Citigroup Inc, U.S. District Court for the Southern District of New York, No. 10-07820.
(Reporting by Grant McCool; editing by Gerald E. McCormick editing by Andre Grenon)