Meanwhile, Bass said the firm’s compensation system has always been a meritocracy that has nothing to do with gender. “We’re compensated based on value to clients and quality of our legal work. We prefer a closed system because it enables a more collegial atmosphere to exist.”

Bass also said every year the number of women who are big originators of new business increases as does the number of women who receive top compensation.

Bass also said that the EEOC only looked at a handful of lawyers in a single office, not compensation figures firm-wide. Greenberg has 1,700 lawyers in 35 offices worldwide. “If they had firm-wide information, I feel confident that [it] will prove our numbers are merit based and not gender skewed.”

According to the lawsuit, Greenberg operates with three levels of shareholders with the top tier earning $1 million more a year than other levels. Less than 10 percent of shareholders at that highest level are women. Griesing says Greenberg routinely assigns female shareholders to lower levels while assigning similarly or lesser-qualified males to higher levels.

In 2011, the firm ranked 193rd out of 221 top law firms in the number of female equity partners, according to the National Law Journal Women in the Equity Partnership: How Firms Fare. Women represented only 9.6 percent of Greenberg’s equity shareholders, well below the national average of 15 percent for the 250 largest firms.

Griesing says when she raised complaints of pay discrimination to firm management and to Bass, the law firm management retaliated against her by denying her equal access to client work, refusing to compensate her in a timely manner and even threatening to sue her for defamation if she pursued her claims against the firm.

Griesing, a commercial litigator, now has own her law firm in Philadelphia with a half-dozen attorneys.

Prior to joining Greenberg, she was a cum laude graduate of the University of Pennsylvania Law School and served as chair of litigation of Philadelphia’s City Solicitor’s Office under former Mayor Edward G. Rendell, who later served as governor of Pennsylvania.