The federal Equal Employment Opportunity Commission is suing a Maryland insurance regulatory agency over allegations that it paid female employees less than their male counterparts.

The EEOC filed a lawsuit against the Maryland Insurance Administration in U.S. District Court in Baltimore last week on behalf of three women who work as investigators or enforcement officers in the agency’s Baltimore office.

“It’s not just unfair when women are paid less than men when they do substantially equal work under similar working conditions — it’s a blatant violation of federal law,” Debra M. Lawrence, an EEOC regional attorney, said in a statement. “The EEOC is committed to ensuring that all employees, both public sector and private sector employees, receive the equal pay they deserve.”

The Maryland Insurance Administration, which is an independent state agency, “strongly” denies the allegations, spokeswoman Vivian D. Laxton said.

“The case will be vigorously defended,” she said in an e-mail.

The agency regulates the insurance industry, enforces insurance laws and investigates complaints that state residents have about their insurance coverage.

“It’s ironic and disturbing that a state law enforcement agency would pay female investigators and enforcement officers less than their male colleagues simply because of their gender,” Spencer H. Lewis Jr., the EEOC’s Philadelphia district director, said in a statement.

According to the EEOC complaint, the Maryland Insurance Administration has paid Alexandra Cordaro, Mary Jo Rogers and Marlene Green less than their male colleagues since December 2009. The lawsuit alleges that other women have also been discriminated against.

The complaint accuses the agency of violating the Equal Pay Act of 1963, which prohibits sex-based wage discrimination between men and women who perform jobs that require substantially equal skill, effort and responsibility under similar working conditions.

The EEOC is asking a jury to order the agency to stop paying wages based on gender, to create and carry out policies and programs that provide equal employment opportunities for women, and to pay back wages and damages to the defendants.