SAN FRANCISCO - Google is facing allegations that it underpays female employees of the company's childcare center.

Heidi Lamar, Google's former employee, alleged in a complaint that female teachers were paid lower salaries than men with fewer qualifications doing the same job at the tech giant.

Lamar's allegation is part of a revised gender-pay lawsuit filed on Wednesday. The earlier version of this complaint, filed by three other women who also used to work for Google, had been rejected by a judge for being "overly broad."

The three former employees were engineer, sales and at management post before leaving the tech company.

Lamar, who had a master degree in teaching and five years experience in similar job before joining Google, said her starting salary was $18.51 per hour, while at the same time, her male colleague was offered $21 per hour.

That means his salary was 13 percent higher than hers even though, she alleged, he had only three years' experience and no master's degree in teaching.

"The biggest difference was that he's a man," she said. "My first reaction was to immediately feel angry and insulted."

Lamar said her case was not alone in Google's childcare center. She said she knew of only one woman hired during her time at Google who started at a higher rate than her, and she had over 10 years of experience.

Google spokeswoman Gina Scigliano said the company disagrees with the "central allegations of this amended lawsuit."

"Job levels and promotions are determined through rigorous hiring and promotion committees, and must pass multiple levels of review, including checks to make sure there is no bias in these decisions," Scigliano said in a statement.

The initial version of this lawsuit sought class action status for all women who worked at Google in California for the past four years, and was rejected for being overly broad.

The amended version proposes a narrower class of plaintiffs that includes engineering, research, management, sales and teaching staff.