Same-sex couples in Nevada County may have to wait a bit longer before they can tie the knot, as guidelines come down from the state and a rehearing petition makes it way to the court.

The Nevada County Clerk's office is awaiting directions from the California Office of Vital Records before issuing marriage licenses to same-sex couples, Gregory Diaz, Nevada County Clerk-Recorder and Commissioner of Civil Marriages, said Friday.

Such marriages became possible after the California Supreme Court ruled 4-3 Thursday to overturn a state law defining marriage as between a man and a woman.

But leaders of the conservative Alliance Defense Fund said they would ask the court to postpone putting its decision into effect until after the fall elections. That's when voters likely will have a chance to vote on a proposed amendment to California's constitution that would bar same-sex couples from wedding.

A petition for rehearing must be filed within 15 days and must be ruled on before the court's decision is final, the county elections office said.

If the court does not grant the request, gay marriages could begin in California in as little as 30 days, the time it typically takes for the justices' opinions to become final.

The Court of Appeals will issue a mandate to ensure county clerks and other local officials adhere to the court's decision statewide while enforcing marriage laws in their jurisdictions, the county elections office said.

Diaz will keep the community informed of the state's progress in implementing the court's decision, the elections office added.

California's secretary of state is expected to rule by the end of June whether sponsors of a measure banning same-sex marriage have gathered enough signatures to put the constitutional amendment on the ballot.

The most recent polls, conducted in 2006 and 2007, found that 51 percent and 49 percent, respectively, of survey respondents opposed making same-sex marriage legal, while 43 percent and 45 percent endorsed the idea.

The amendment needs a simple majority to pass, and if the voters reject gay marriage, their decision will supersede the high court's. Leaders of the two sides said they plan to spend at least $25 million combined on the campaign.

Republican Gov. Arnold Schwarzenegger, who has twice vetoed legislation that would have granted marriage to same-sex couples, said in a statement that he respected the court's decision and "will not support an amendment to the constitution that would overturn this state Supreme Court ruling."

To contact Staff Writer Soumitro Sen, e-mail ssen@theunion.com or call 477-4229.