Goldman Sachs Group Inc was sued for alleged bias by a former vice president, who said the Wall Street bank consigned her to a mommy-track that led to her firing while she was on maternity leave.

The lawsuit was filed Wednesday in Manhattan federal court by Charlotte Hanna, who said she worked at Goldman Sachs University, an orientation program for new analysts, associates and summer interns.

Hanna, a Manhattan resident, alleged that after her 2005 return from her first maternity leave, Goldman demoted her and made her feel unwelcome in what had become a boys-only club.

She said she was fired in February 2009, a week before she was to return from a second maternity leave.

When Ms. Hanna decided to take the 'off-ramp' provided by the firm to devote time to her children, there was no 'on-ramp' that enabled her to return to full-time employment, the complaint said. Essentially, the 'off-ramp' was a direct path to a mommy-track that ultimately derailed Ms. Hanna's career.

Goldman did not immediately return a request for comment.

Major U.S. investment banks are regularly targets of lawsuits by former workers who allege some form of discrimination. Hanna's age was not immediately available.

According to the complaint, Hanna joined Goldman in 1998 as an associate, was promoted to vice president two years later, and received strong praise for her work.

It said she took advantage of a Goldman program letting her work part-time upon returning from her first maternity leave in February 2005.

Upon her return, Hanna allegedly hit a glass ceiling with respect to pay and advancement, was demoted, and was systematically excluded from operations and social functions.

The complaint said 75 percent of those selected for termination in her group had recently taken maternity leave.

It is clear that Goldman Sachs views working mothers as second-class citizens who should be at home with their children, the complaint said.

Hanna's lawyer is Douglas Wigdor, a partner at Thompson Wigdor & Gilly LLP. He said he also represents five women suing Citigroup Inc for alleged discrimination.

We have seen more gender and pregnancy discrimination cases since the economy began its downturn, Wigdor said.

I attribute it to the fact that managers are typically men who have unfettered discretion about who to terminate, he went on. They perceive that working mothers may not work as hard as men, and may not be with the firm as long so they can be with their children. That can make women seem more expendable.

The case is Hanna v. Goldman Sachs & Co et al, U.S. District Court, Southern District of New York, No. 10-02637.

(Reporting by Jonathan Stempel, editing by Gerald E. McCormick)