SAN FRANCISCO – Less than a month after a bill to legalize same-sex marriage died in the California Assembly, a Democratic lawmaker said he plans to revive the measure this session by attaching it to legislation already pending in the state Senate.

Assemblymember Mark Leno, one of six openly gay members of the Legislature, said he has decided to employ a legislative maneuver known as “gut and amend” to resurrect the bill that on June 2 fell four votes shy of gaining the simple majority it needed to pass the 80-member house.

“My hope is that we will have a bill amended by the end of this week or the beginning of next,” said Leno, declining to offer specifics on which legislation he plans to rewrite. “We intend to do this.”

Leno’s bill would have changed the California family code to define marriage as between “two persons” instead of as between a man and a woman. To bring it back to life, he can substitute his measure’s language into a bill that successfully passed from the Assembly to the Senate.

If it passes Senate committees and makes it off the Senate floor, it would be the first time a legislative chamber in the nation has voted to give same-sex couples the same rights as heterosexual spouses. The measure would have to return to the Assembly for another round of voting before it could be sent to Gov. Arnold Schwarzenegger.

Before AB 19 failed in the Assembly, it was expected to have an easier time in the state Senate, where Democrats hold a 25-15 edge over Republicans. Geoffrey Kors, executive director of the gay rights lobbying group Equality California, said supporters already are working to shore up support in the Senate.

“From a national perspective it is extremely important for us to have a legislative victory,” Kors said. “If one house, be it the Assembly or Senate of the California Legislature, votes in favor of marriage equality, it totally undercuts President Bush and the extreme right-wing argument that this is simply a few judges who are ruling on the issue.”

A San Francisco judge ruled in March that state laws prohibiting same-sex couples from marrying are unconstitutional. The state attorney general has appealed, and the case is likely to wind up before the California Supreme Court within the next year.

While it took a court order for Massachusetts last year to become the first state to grant marriage rights to same-sex couples, gay rights advocates had looked to California to be the first Legislature to do so voluntarily.

Opponents of same-sex marriage also have begun the process to put a constitutional amendment before voters that would ban same-sex nuptials and strip gay and lesbian couples of domestic partnership benefits. They hope to get the initiative on the June 2006 ballot.

Randy Thomasson, president of the Campaign for Children and Families, predicted that Leno’s gambit would give momentum to that effort.

“Mark Leno, be careful what you wish for,” Thomasson said. “The Democrat politicians’ obsession with destroying the essence of marriage will keep this issue front and center for California voters.”