CONCORD, N.H. - New Hampshire lawmakers voted yesterday to authorize civil unions and sent the measure to Gov. John Lynch, who announced last week that he would sign it.

The Senate passed the bill, 14-10, along party lines, Democrats in favor and Republicans opposed.

"This legislation is a matter of conscience, fairness, and of preventing discrimination," said the governor's spokesman, Colin Manning. "It is in keeping with New Hampshire's proud tradition of preventing discrimination."

Three other states already offer civil unions for gay couples: New Jersey, Connecticut and Vermont. Neighboring Massachusetts in 2004 became the only state to allow same-sex marriage.

Unlike other states, there was no active court challenge to push New Hampshire to act on the issue.

In fact, the success of civil-union legislation was an about-face from two years earlier, when a study panel recommended that New Hampshire give no meaningful consideration to extending legal recognition to gay couples.

That panel had concluded that homosexuality was a choice, and it endorsed a constitutional amendment to limit marriage to unions between a man and a woman. State lawmakers have defeated proposed constitutional bans on same-sex marriage two years in a row.

Sponsors of the civil-unions bill called it a door to marriage in all aspects but name. Opponents argued it would lead to the collapse of traditional values.

"Let's just call it what it really is, no sugarcoating," said Republican Sen. Robert Letourneau. "This creates same-sex marriage. There is no right to marriage in either the New Hampshire Constitution or the federal Constitution.

"We don't let blind people drive or felons vote, all for good and obvious reasons," he said.

State Rep. Jim Splaine, who is openly gay, said time would change those attitudes.

"As we continue to evolve this discussion, we'll see people not worried so much about the marriage word," he said. "This is an important difference. This is not marriage. This is civil union. This does nothing to impact anyone's marriage."

The measure would take effect Jan. 1.