Six former and current employees of Bayer AG’s U.S. health care arm filed a $100 million gender discrimination lawsuit Monday, claiming the U.S. unit discriminates against its female employees in terms of pay and promotion, as well as pregnancy leave.

The lawsuit, filed in federal court in Newark, N.J., seeks class-action status and is asking for $100 million in back pay, damages and legal costs. It’s the latest in a series of lawsuits alleging discrimination against women by major companies operating in the U.S.

“Bayer engages in systemic discrimination against its female employees — particularly those with family responsibilities — by paying them less than their counterparts, denying them promotions into better and higher paying positions, limiting their employment opportunities to lower and less desirable job classifications, and exposing them to different treatment and a hostile work environment,” said Katherine Kimpel, a lawyer for the women suing. “To make matters worse, Bayer is often blatant about its disregard for its female employees.”

The defendants include Bayer HealthCare Pharmaceuticals and its U.S. parent Bayer Corp., a unit of Bayer AG.

The lawsuit alleges the “dearth in female leadership” at Bayer HealthCare Pharmaceuticals is a contributing factor and a cause of ongoing and pervasive discrimination against female employees at Bayer.

The complaint claims female employees who have complained to upper-level management: “You know better. The company won’t do anything about that.” The lawsuit also claims that the company’s human resources department has characterized gender discrimination as a “gray area” that should be handled by the employee, not the company.

A Bayer spokeswoman said the company had previously received administrative complaints before the Equal Employment Opportunity Commission by six current or former New Jersey-based employees. The company was prepared to cooperate fully with the EEOC and respond to the charges, but the plaintiffs elected to end those proceedings and file the lawsuit, the spokeswoman said.

“Bayer denies the allegations of gender discrimination and will vigorously defend itself against these charges,” the spokeswoman said. “Bayer will not comment further on pending litigation, other than to note that it is committed strongly to a policy of non-discrimination and equal treatment for all employees.”

A number of corporations who do business in the U.S. have faced discrimination suits on behalf of their female employees.

Last month, Sanford Wittels & Heisler, which brought the Bayer suit, sued Toshiba Corp.’s U.S. business and French advertising company Publicis Group SA on behalf of female employees in the U.S.

In July, Novartis AG’s U.S. unit agreed to pay $175 million to settle a long-running discrimination suit brought by Sanford Wittels. The settlement followed a $253 million jury verdict against the company.

In September, three women who formerly worked for Goldman Sachs Group Inc. sued the investment bank alleging the firm discriminates against women in pay and promotions.

Later this year, the U.S. Supreme Court is expected to hear a 2010 lawsuit on behalf of as many as 1.5 million female employees at Wal-Mart Stores Inc.