Three former female employees have sued Google alleging that the company has "engaged in systemic and pervasive pay and promotion discrimination" in a lawsuit filed two days ago in San Francisco.

The women claim they were paid less than men, frequently assigned to lower paying jobs, and promoted less often than men in similar jobs. The lawsui asks a judge to certify it as a class action and seeks wages, interest and damages.

Google spokeswoman, Gina Scigliano however denies the claims made in the lawsuit saying "we disagree with the central allegations".

One of the women, a software engineer Kelly Ellis, was hired in 2010. Prior to that, she had worked as an engineer after graduating from the University of Virginia in 2006 according to the complaint, Google assigned her to Level 3 on the software engineering team the slot on the Google career ladder for new college graduates but weeks after Ellis was hired, the company hired a male software engineer, who had also graduated in 2006 but he was put on the higher-paying Level 4.

Ellis went on to receive strong performance reviews at Google but, the complaint alleges, was initially denied a promotion to Level 4. She eventually got the promotion before leaving Google in 2014, according to the suit. "But by that time, her male counterparts were on their way to even higher levels and compensation for similar work, ensuring she could never catch up on the gender pay gap," the complaint states.

Holly Pease and Kelli Wisuri, the other plaintiffs in the suit, tell similar stories in the complaint. Wisuri was paid less than men for "substantially equal or similar work" than her male counterparts, the complaint says. The suit cites a U.S. Department of Labor analysis of data on 21,000 Google employees for 2015. "That analysis found 'systemic compensation disparities against women pretty much across the entire workforce,'" the complaint says. Google has said its own our analysis of its employees' compensation indicated it had no gender pay gap.