BOSTON —  The Massachusetts Legislature on Wednesday rejected a proposed constitutional amendment that sought to ban gay marriage (search) but legalize civil unions, a year after the state performed the nation's first government-sanctioned same-sex weddings.

It was the second time the Legislature had confronted the measure, which was intended to be put before voters on a statewide ballot in 2006. Under state law, lawmakers were required to approve it in two consecutive sessions before it could move forward.

After less than two hours of debate Wednesday, a joint session of the House and Senate voted 157-39 against the measure.

It was a striking departure from a year earlier, when hundreds of protesters converged on Beacon Hill (search) and sharply divided legislators spent long hours debating the issue. In that session, in March 2004, lawmakers voted 105-92 in favor of the amendment.

This year, the crowds were tamer and some legislators who had initially supported the proposed change to the state constitution said they no longer felt right about denying the right of marriage to thousands of same-sex couples.

"Gay marriage has begun, and life has not changed for the citizens of the commonwealth, with the exception of those who can now marry," said state Sen. Brian Lees (search), a Republican who had been a co-sponsor of the amendment. "This amendment which was an appropriate measure or compromise a year ago, is no longer, I feel, a compromise today."

The proposal also was opposed by critics of gay marriage, who want to push for a more restrictive measure.

"The union of two women and two men can never consummate a marriage. It's physically impossible," said state Rep. Phil Travis, a Democrat. "The other 49 states are right and we are wrong."

Lawmakers already are preparing for a battle over another proposed amendment that would ban both gay marriage and civil unions. The earliest that initiative could end up on the ballot is 2008.

The state's highest court ruled in November 2003 that same-sex couples had a right under the state constitution to marry. The first weddings took place on May 17, 2004 — two months after lawmakers began the process of trying to change the constitution to reverse the court's ruling.

Since then, more than 6,100 couples have married.

Within a year of the first Massachusetts marriages, 11 states pushed through constitutional amendments banning gay marriage, joining six others that had done so earlier.

The Connecticut Legislature approved civil unions in April, joining Vermont in creating the designation that creates the same legal rights as marriage without calling it such. Earlier this month, California lawmakers passed legislation legalizing same-sex marriage, though Gov. Arnold Schwarzenegger has promised to veto it.

Although more than 6,100 same-sex couples were married in Massachusetts, the state barred out-of-state couples from getting married here, citing a 1913 law that prohibits couples from marrying in Massachusetts if their union would be illegal in their home states. A lawsuit challenging the legality of that law is pending before the SJC.