The U.S. Equal Employment Opportunity Commission has won summary judgment in its lawsuit against Baltimore County, Md., that alleged its pension plan is discriminatory based on age.

The lawsuit, originally filed in 2007, claimed that Baltimore County's pension plan, known as the Employee Retirement System, violated the Age Discrimination in Employment Act by requiring employees 40 years or older to pay higher pension contributions, the EEOC said in a statement Monday.

In 2010, the 4th U.S. Circuit Court of Appeals in Richmond, Va., vacated an entry of summary judgment by the U.S. District Court for the Northern District of Maryland, Northern Division, in Baltimore, in favor of Baltimore County. The appeals court sent the case back to the lower court to decide whether permissible financial considerations support the pension plan, according to court documents.

U.S. District Court Judge Benson Everett Legg last week granted summary judgment against Baltimore County in favor of the EEOC, noting that Baltimore County failed to show financial considerations for requiring older employees to contribute more to the plan that were not based on age.

“The county has come forward with no evidence demonstrating why two workers with the same number of years until retirement eligibility should be required to contribute to the ERS at different rates,” the judge wrote.

"The county made older employees pay more than younger employees for the same retirement benefits, without any financial justification,” said EEOC regional attorney Debra Lawrence, in the statement. “Older employees felt the impact of this discrimination in every paycheck.”

In its official blog site, Baltimore County said the court’s ruling on age discrimination is wrong and would force employees to pay more, Baltimore County Budget and Finance Director Keith Dorsey wrote.

“To put it simply, Baltimore County's retirement contribution schedule is not discriminatory, was negotiated by county labor groups, and is supported by years of sound actuarial studies,” Mr. Dorsey wrote. “For a court to attempt to force Baltimore County to raise the pension contributions for nearly 8,000 county employees retroactively is simply wrong, and the county will stand with its employees and fight this case until there is no one left to fight.”

Baltimore County intends to “to vigorously pursue this case and are considering our legal options,” a spokeswoman said in an email.

The next phase of litigation will determine damages, the EEOC said.