SAN FRANCISCO — Same-sex marriage was on hold in California after opponents petitioned a federal appeals court Tuesday to review a split decision by three of its judges that struck down a voter-approved measure that limited marriage to a man and woman.

Lawyers for the religious and legal groups asked the 9th U.S. Circuit Court of Appeals to rehear the 2-1 decision that declared the ban, known as Proposition 8, to be a violation of the civil rights of gay and lesbian Californians.

If they had not sought reconsideration, the three judges could have ordered the ruling to take effect in another seven days, clearing the way for same-sex marriages to resume in the state.

Instead, same-sex marriages will remain on hold at least until the 9th Circuit decides to accept or reject the rehearing petition. The court does not face a deadline for doing so.

"This gives the entire 9th Circuit a chance to correct this anomalous decision by just two judges overturning the vote of seven million Californians," said Andy Pugno, general counsel for the Protect Marriage coalition.

Legal experts said supporters of the ban could be exhausting all their options before trying to take the case to the Supreme Court. Some experts said the 9th Circuit does not often reverse the decisions of member judges.

Six states allow gay couples to wed -- Connecticut, New Hampshire, Iowa, Massachusetts, New York and Vermont -- as well as the Washington capital district. The governor of Washington signed a bill this month that would make that state the seventh. But California, as the most populous U.S. state and home to more than 98,000 same-sex couples, would be the gay rights movement's biggest prize of them all.

Proposition 8 amended the California Constitution to outlaw same-sex marriages five months after the state Supreme Court threw out a pair of statutes that limited marriage to a man and woman. The proposition was approved by voters in November 2008 with 52 per cent of the vote.

"Today's petition shows how far the anti-marriage proponents of Proposition 8 will go to ensure that gay and lesbian Americans remain second-class citizens," said Chad Griffin, president of the American Foundation for Equal Rights, which sued to overturn the ban. "Separate is never equal -- and I am confident that one day, very soon, every American will be able to enjoy the fundamental freedom to marry."

The 9th Circuit panel said in its Feb. 7 ruling that the amendment violated the U.S. Constitution's promise of equal protection because it singled out a minority group for disparate treatment for no compelling reason.

The two judges in the majority concluded that the law had no purpose other than to deny gay couples marriage, since California already grants them all the rights and benefits of marriage if they register as domestic partners.

The lone dissenting judge insisted that the ban could have served a legitimate purpose in the minds of its supporters: namely, helping to ensure that children are raised by married, opposite-sex parents.

All three judges agreed there was no evidence that former Chief U.S. Judge Vaughn Walker, who struck down the ban after conducting a 13-day trial, should have disclosed that he was gay and in a long-term relationship with another man before he presided over the proceedings.