NEW YORK, March 21 (Reuters Legal) - Six former and current employees of a U.S. unit of Bayer AG filed a class-action lawsuit against the company on Monday, alleging gender discrimination in pay, promotions and the treatment of pregnant women and mothers.

The lawsuit, filed against Bayer HealthCare Pharmaceuticals in New Jersey federal court, sought $100 million in lost pay and benefits as well as compensatory and punitive damages.

The plaintiffs, women who served at the associate-director level or higher, blamed a male-dominated management team for fostering an environment that was hostile to women. According to the complaint, internal company communications stated a preference for men in leadership roles and described women as loose cannons prone to mood swings, indecision, and backstabbing.

The complaint also cited examples of overt hostility toward motherhood and pregnancy, including the denial of promotions for women who took maternity leave and a senior manager's alleged statement that he needed to stop hiring women of reproductive age.

The company denied all allegations of gender discrimination and said it would vigorously defend itself against the charges. The company is committed to nondiscrimination and equal treatment for all employees, it said in a statement.

The lawsuit is the latest in a string of gender discrimination class actions filed by Sanford Wittels & Heisler against large corporations on behalf of female employees. On March 3, the firm filed a suit against health insurer Cigna Corp for allegedly blocking women from promotions and higher-paying jobs. The same firm sued Publicis Groupe on February 24, describing the multinational advertising conglomerate's glass ceiling as a cement wall.

The flurry of suits is a symptom of the bad economy, said Katherine Kimpel, the plaintiffs' lawyer in the case against Bayer HealthCare Pharmaceuticals. Companies have felt emboldened in the past few years to begin to be more open and more blatant in their discrimination against women in the workplace on the assumption that they can use the excuse of a bad market to disguise a multitude of sins, she said.

Kimpel recently served as lead counsel in a gender-discrimination lawsuit against Novartis AG, winning a $253 million verdict against the pharmaceutical company last May.

Perhaps the most-watched gender bias suit is Wal-Mart Stores v. Dukes, scheduled for oral arguments before the Supreme Court on March 29. The main issue in that case is the number of plaintiffs to be included in the lawsuit, with over a million female workers currently in the certified class. Wal-Mart has sought to undo the class certification, arguing that the female employees held different jobs in different states under the supervision of different managers.

(Reporting by Terry Baynes of Reuters Legal; Editing by Eddie Evans and Eric Effron)