Three gay couples are suing California's giant public pension fund and the Internal Revenue Service to make long-term care insurance available to the same-sex spouses of state government workers.

The Legal Aid Society-Employment Law Center filed the federal lawsuit Tuesday in San Francisco on behalf of the three married couples.

Lawyer Claudia Center says the California Public Employees' Retirement System is violating the couples' civil rights by making gay spouses ineligible for the program.

Pension fund spokesman Brad Pacheco says the agency makes the rest of its benefits available to gay spouses but that the long-term care program must abide by federal law, which does not recognize same-sex unions.