LOS ANGELES - La Mirada resident Rob Anders was set to visit his 89-year-old mother in Florida for a family reunion last month.

Anders, a longtime airline industry employee, won round-trip domestic airfare on Northwest Airlines for him and a companion at his company holiday party last December. But when he tried to redeem the tickets for him and his registered domestic partner, Northwest refused.

"I felt terrible," said Anders, who has lived with his partner for 15 years. "I thought what they were doing was unfair."

A representative from Northwest Airlines told Anders that the airline would only recognize a spouse, another airline employee, or a dependent child as a companion. The representative specifically stated Northwest Airlines would not recognize a registered domestic partner as a "spouse" for the tickets.

"What happened to Mr. Anders and his partner violates California law and is clearly discriminatory," said Christine P. Sun, ACLU of Southern California staff attorney. "We are asking that the company not discriminate on the basis of sexual orientation or marital status and honor Mr. Anders' ticket for him and a companion."

In a letter to Northwest Airlines sent Thursday, Sun wrote that the Unruh Civil Rights Act, part of California law "mandates 'full and equal accommodations, advantages, facilities, privileges, or services in all business establishments of every kind whatsoever' without regard to sexual orientation or marital status."

"Because same-sex couples who wish to marry cannot currently do so under California law, using marriage as a criterion discriminates on the basis of sexual orientation. Sun said. "Northwest's policy also discriminates on the basis of marital status because it does not permit unmarried heterosexual individuals to bring the companion of their choice."

Anders, who is 60, has lived in Southern California since 1971. He and his partner Pat registered as domestic partners in California in 2004. Anders is part of many local civic groups and has traveled the world.