ALBANY - Senate Majority Leader Joseph Bruno signaled Thursday that he may challenge Gov. David A. Paterson's directive to state agencies requiring them to recognize same-sex marriages performed in other jurisdictions.

Paterson emphasized Thursday that he made no new law with his May 14 order, but was simply heeding a recent Appellate Division court ruling and New York's legal tradition of honoring marriages that are valid elsewhere. If Paterson hadn't issued the directive, he said, he'd have left the state exposed to costly litigation.

“I'm following the law as it always existed,” the Democratic governor said.

But Bruno, who as the state's top Republican has blocked efforts to legalize gay

marriage in New York, was clearly irritated at not receiving advance notice of the move. He said Paterson might have violated the state constitution's separation of powers clause, adding he would confer with attorneys about a possible challenge.

Bruno also said his Republican majority in the Senate remains opposed to legislation to legalize gay marriage. “We've said we're not going to pass that bill. It would be unconstitutional right now. It would be tested in the courts anyway.”

Even as conservatives assailed Paterson's directive as an end-run around the legislature Thursday, gay-rights organizations hailed it as a step likely to have a far-reaching impact on life for gay couples, and one that paves the way for eventual legalization of same-sex marriage here.

“It means a lot,” said Alan Van Capelle, executive director of the Empire State Pride Agenda. “For five years now, New Yorkers have been traveling to places like Canada and coming back with marriage licenses. ... Now they will be able to access the 1,324 different rights and responsibilities that come with a marriage license in New York - and that's significant.”

Just how the rules for married gay couples will change will be the subject of intensive discussion over the next several weeks. Paterson has given state agencies until June 30 to analyze the impact of his directive, but some things seemed clear to Van Capelle and the New York Civil Liberties Union: For example, in New York, vending, alcoholic beverage, commercial fishing and other valuable business licenses can be inherited by a spouse.

Married gay couples would confront new obligations as well, such as conflict of interest rules for banks and government that require them to disclose their spouse's finances.

A spouse will likely be able to transfer land and autos tax free, but whether same-sex couples can file joint tax returns is doubtful. New York follows the lead of the Internal Revenue Service on filing status, and the federal Defense of Marriage Act bars same-sex couples from filing federal returns jointly. But some experts said Paterson's directive could lead the state to revise that practice.

As civil rights advocates evaluated Paterson's directive Thursday, it was already drawing fire from conservatives such as Mike Long, chairman of the state Conservative Party, who insisted “marriage is between a man and a woman.”

Dan Weiller, a spokesman for Assembly Speaker Sheldon Silver called Paterson's action “consistent” with the Assembly's vote last year to legalize marriage, a measure that got nowhere in the Senate.

And Comptroller Thomas DiNapoli also praised Paterson's directive, noting that last September he directed the state retirement system to recognize same-sex marriages from other jurisdictions.