Monica Prestia, who began working for Bloomberg LP as a sales representative in 1997, filed a suit in June claiming the company discriminated against her after she became pregnant in February of 2005.
The company treated her differently than similarly employed male workers and subjected her to "harassment, hostile work environment and other forms of discrimination," the complaint said.
The suit seeks unspecified damages and is pending in court.
On Thursday, the EEOC accused the New York-based company of similar discrimination, saying it engaged in a pattern of demoting women, diminishing their duties and excluding them from job opportunities after they disclosed they were pregnant.
Bloomberg LP spokeswoman Judith Czelusniak did not respond to a request for comment on the Prestia case; in court papers the company denied the allegations. About the EEOC suit on Thursday, Czelusniak said: "We believe strongly that the allegations are without merit and we intend to defend the case vigorously."
The agency brought the suit on behalf of three senior employees who had filed complaints with the EEOC regarding Bloomberg LP, saying the activities occurred with malice or reckless indifference to federal anti-discrimination laws. The EEOC is the federal agency charged with interpreting and enforcing laws passed to prevent discrimination in the workplace.
The women were expected to bring their own motion in court next week that further details their claims. They were identified by the EEOC as Tanys Lancaster, Jill Patricot and Janet Loures.
Lancaster was said to be earning close to $300,000 in a senior position in the company's Transaction Products Department when she announced her pregnancy.
"Almost immediately I began to suffer demotions, decreases in compensation as well as retaliation after I complained to Human Resources," she said in a statement.
Lancaster is no longer employed with Bloomberg. Patricot and Loures are still working there.
Patricot, who worked as a manager in the Global Data Division, claims that after returning to her job following maternity leave, she was demoted to an entry level position because her schedule had changed due to child care demands.
Loures was also a manager in the Global Data Division, and said her duties and staff were reduced starting with her first maternity leave and continuing through a second one. She is now employed in an entry-level clerical position, the EEOC said.
The EEOC said the women's claims of discrimination due to gender and pregnancy "were echoed by a number of other female current and former employees who have taken maternity leave."
Richard Roth, an attorney for the woman in the separate suit filed in June, said in an interview Friday that the EEOC complaint "helps expose what's really going on behind the scenes at Bloomberg."
It is a culture that Michael Bloomberg, who is a potential presidential candidate, was accused of fostering while he headed the company. Bloomberg stepped down as CEO to run for mayor in 2001 but retains a 68 percent stake in the company. A spokesman for Bloomberg declined to comment on the cases Friday.
While Bloomberg was CEO, a female sales executive accused him in a lawsuit of sexual harassment and other claims similar to these new allegations.
The suit, filed by Sekiko Sakai Garrison in 1997, claimed that he and other male managers displayed a discriminatory attitude toward pregnant women and new mothers.
It said that when he found out Garrison was pregnant, he told her "Kill it!" and said "Great! Number 16!" -- an apparent reference to the number of women in the company who were pregnant or had maternity-related status at the time.
It also claimed Bloomberg and other men at the company made "repeated and unwelcome" sexual comments, overtures and gestures, contributing to an offensive, locker-room environment.
Bloomberg adamantly denied the accusations; the suit was settled in 2000. Terms were not disclosed.
