Lawmakers in the U.S. state of New York have voted to approve same-sex marriage, handing American gay rights advocates a major victory in their quest for equality.

After extensive debate, the New York State Senate approved the legislation Friday night by a vote of 33 to 29, as two previously undecided Republican lawmakers cast the deciding votes in favor of the law. The Democrat-controlled state Assembly, which approved a different version of the law last week, is now expected to approve the new version and Governor Andrew Cuomo is expected to sign the legislation into law.

When the final approval is given, New York would become the sixth U.S. state where gay couples can wed, and by far the largest. Gay couples would be able to begin marrying in the state within 30 days.

New York could become a magnet for such marriages because the state has no residency requirement for obtaining a marriage license.

Activists consider New York's approval particularly significant since it is the third largest U.S. state and because of New York City's international stature. The city also is considered to be the birthplace of the gay rights movement, with the Stonewall riots in the city's Greenwich Village community in 1969.

The state Senate debate over the last several days centered on providing legal protections for religious groups opposed to same-sex marriages that feared they would be sued for discrimination if they refused to allow their facilities to be used for gay weddings. The lawmakers agreed on language allowing religious organizations to refuse to perform such marriages or provide space for them.

One of the pivotal Republicans, State Senator Stephen Saland, had voted against a similar bill two years ago, but on Friday pledged the deciding vote in favor the law. He called his change of heart “a vote of conscience” and said he was “doing the right thing.”

Gay couples in the legislative gallery wept as they listened to his speech.

When the New York law is enacted, the state will join Vermont, New Hampshire, Connecticut, Massachusetts, Iowa and Washington, D.C. in allowing gay couples to marry.

The legislative debate coincided with President Barack Obama's speech Thursday before a group of gay rights supporters at a campaign fundraising event in New York City.

Mr. Obama told the crowd that gay couples deserve the same legal rights as any other couple in this country, but he did not fully endorse same-sex marriage. The president has upset gay rights activists for his support of civil unions over marriage, but recently said his views on the matter are “evolving.”

Mr. Obama defended his administration's record on gay rights, including repealing the ban on homosexuals serving in the military, and ordering the Justice Department to stop defending a law that narrowly defines marriage as that between a man and a woman.