By LISA LEFF, AP

SAN FRANCISCO (March 14) - A judge ruled Monday that California's ban on gay marriage is unconstitutional - a legal milestone that, if upheld on appeal, would open the way for the most populous state to follow Massachusetts in allowing same-sex couples to wed. Judge Richard Kramer of San Francisco County's trial-level Superior Court likened the ban to laws requiring racial segregation in schools, and said there appears to be ''no rational purpose'' for denying marriage to gay couples. The ruling came in response to lawsuits filed by the city of San Francisco and a dozen gay couples a year ago after the California Supreme Court halted a four-week same-sex marriage spree started by Mayor Gavin Newsom. The opinion had been eagerly awaited because of San Francisco's historical role as a gay rights battleground Gay marriage supporters hailed the ruling as a historic development akin to the 1948 state Supreme Court decision that made California the first state to legalize interracial marriage. ''Today's ruling is an important step toward a more fair and just California that rejects discrimination and affirms family values for all California families,'' San Francisco City Attorney Dennis Herrera said.

AP The court case involves marriages allowed last year by San Francisco Mayor Gavin Newsom, center.   Talk About It: Post | Chat

Conservative leaders expressed outrage at the ruling and vowed to appeal.

''For a single judge to rule there is no conceivable purpose for preserving marriage as one man and one woman is mind-boggling,'' said Liberty Counsel President Mathew Staver. ''This decision will be gasoline on the fire of the pro-marriage movement in California as well as the rest of the country.

Last winter, nearly 4,000 gay couples got married after Newsom instructed the city to issue them licenses, in defiance of state law. The California Supreme Court later declared those marriages void, saying the mayor overstepped his authority. But the court did not address the underlying issue of whether the law against gay marriage violates the California Constitution.

At issue in the current case were a 1977 law that defined marriage as ''a personal relation arising out of a civil contract between a man and a woman,'' and a voter-approved measure in 2000 that amended the law to say more explicitly: ''Only marriage between a man and a woman is valid or recognized in California.''

Gay marriage opponents were particularly upset by the judge's decision to nullify to 2000 proposition - approved by 61 percent of voters.

''The practical effect is the disregard of close to two-thirds of the people of California who used the initiative process to ensure that marriage would remain between one man and one woman,'' said Robert Tyler, an attorney for the Alliance Defense Fund.

The state maintained that tradition dictates that marriage should be limited to opposite-sex couples. Attorney General Bill Lockyer also cited the state's domestic-partners law as evidence that California does not discriminate against gays.

But Kramer rejected that argument, citing Brown v. Board of Education - the landmark U.S. Supreme Court decision that struck down segregated schools.

''The idea that marriage-like rights without marriage is adequate smacks of a concept long rejected by the courts - separate but equal,'' the judge wrote.

It could be months or years before the state actually sanctions same-sex marriage, if ever. Kramer's decision is stayed automatically for 60 days to allow time for appeal.

Lockyer has said in the past that he expected the matter eventually would have to be settled by the California Supreme Court.

A jovial Newsom was flanked by several same-sex couples and their supporters at a City Hall news conference shortly after the ruling was announced. ''We will not be appealing this decision,'' the mayor joked as the crowd broke into laughter.

Two bills now before the California Legislature would put a constitutional amendment banning same-sex marriage on the November ballot. If California voters approve such an amendment, as those in 13 other states did last year, that would put the issue out of the control of lawmakers and the courts.

The decision is the latest development in a national debate that has been raging since 2003, when the highest court in Massachusetts decided that denying gay couples the right to wed was unconstitutional.

In the wake of the Massachusetts ruling, gay rights advocates filed lawsuits seeking to strike down traditional marriage laws in several other states. Opponents responded by proposing state and federal constitutional amendments banning gay marriage.

Around the country, Kramer is the fourth trial court judge in recent months to decide that the right to marry and its benefits must be extended to same-sex couples.

Just as many judges have gone the other way in recent months, however, refusing to accept the argument that keeping gays from marrying violates their civil rights.

California has the highest percentage of same-sex partners in the nation, and its Legislature has gone further than any other in providing gay couples the benefits of marriage without being forced to do so by court order.

AP-NY-03-14-05 21:01 EST

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