ATLANTA (AP) _ Abortion rights advertisements began appearing on city buses as a result of a First Amendment court challenge, but they will be the last issue-oriented ads on the Atlanta transit system.

The Metropolitan Rapid Transit Authority rejected the abortion ads last year, citing its policy banning ads with controversial subjects. But the National Abortion Federation sued, and a federal judge ruled in June that MARTA's reason for rejecting the ads was too vague.

MARTA previously accepted ads concerning gay rights, racial and religious tolerance, AIDS awareness, pregnancy counseling and adoption services but had rejected political ads.

MARTA signed an agreement with the federation Aug. 18 that permits the ads on buses and at bus shelters for three months. The ads, which went up Monday, won't be displayed in MARTA trains, the federation's Stephanie Mueller said Tuesday.

MARTA spokeswoman Dee Baker said the dispute over the abortion ads prompted the agency to revamp its policies. Once the three-month agreement expires, MARTA will allow only commercial ads, she said.