A veteran Cigna Corp (CI.N) manager sued the U.S. health insurer on Thursday, saying it unfairly blocks female employees from promotions and higher-paying jobs.

The lawsuit, filed in U.S. District Court in Boston, seeks $100 million in damages and asks for class-action status.

Bretta Karp, a 14-year-veteran of Cigna, charged in court papers the company last year denied her a promotion because she came across as too aggressive in an interview and went on to take away her largest territories after she complained.

The suit contends the Philadelphia-based company uses its employee-evaluation systems to block female workers from advancing into higher-paid positions by forcing their rankings into a bell curve.

In effect, Cigna bars female employees from better and higher-paying positions which have traditionally been held by male employees, the lawsuit contends.

It charges the company with violating the U.S. Civil Rights Act, as well as Massachusetts laws banning gender discrimination.

The company said it would fight the claims.

We are committed to diversity and equal opportunity; our workplace policies expressly prohibit discrimination in any form and we intend to fully defend against the complaint, spokeswoman Gloria Barone Rosario said in an e-mail.

The Washington law firm representing Karp, Sanford Wittels & Heisler, won a gender discrimination case last year against drugmaker Novartis AG (NOVN.VX). The Swiss company paid $175 million to settle that case after a jury awarded $250 million in damages.

The firm brought a similar lawsuit against Toshiba Corp (6502.T) in January.

GENDER GAP PERSISTS IN U.S.

The suits reflect a culture where Americans for decades have discussed the problem of gender discrimination in the workplace without making much progress in solving it, said Karp's attorney, David Sanford.

U.S. women are paid about 75 percent of what their male peers earn, according to a White House report released on Tuesday, which cited 2009 data.

They are all too familiar examples of a much deeper systemic problem in society, Sanford said of the recent lawsuits. I don't think we've made a lot of progress over the years in closing that gap.

Cigna shares were up 2 percent at $43.39 amid a broad rally in U.S. stocks.

The case is Karp v. Cigna Healthcare, U.S. District Court, District of Massachusetts, No. 11-10361.

(Reporting by Scott Malone; editing by Andre Grenon)

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