In another gay marriage ruling yesterday, the Louisiana Supreme Court unanimously reinstated an anti-gay marriage amendment to the state constitution that was overwhelmingly approved by voters in September.

The high court reversed a ruling by a state district judge, who struck down the "defense of marriage" amendment in October on the grounds that the measure dealt with more than one subject, in violation of the Louisiana Constitution.

But the state Supreme Court said: "Each provision of the amendment is germane to the single object of defense of marriage."

The amendment was put on the ballot by the Legislature and approved by 78 percent of the voters. Eleven other states adopted similar amendments in the fall elections.

"We're obviously delighted," said Michael Johnson, an attorney for Alliance Defense Fund, which argued for the amendment's legality.

Gay-rights activist Chris Daigle called the ruling an outrage, saying it does nothing to defend marriage.

"High divorce rates, high adultery rates, poverty, lack of education, parents having to hold more than one job, those are the real threats to marriage," said Daigle, a state legislative candidate.

But other opponents of the amendment said they were pleased that the court noted that it would not affect the rights of unmarried couples, gay or heterosexual.

In striking down the amendment, Judge William Morvant of Baton Rouge had ruled that it would also prevent the state from recognizing common-law relationships, domestic partnerships and civil unions between gay and heterosexual couples.

At issue was a provision that stated: "A legal status identical or substantially similar to that of marriage for unmarried individuals shall not be recognized."

But the high court said the amendment would not stop unmarried couples from buying property together, making medical decisions for each other or leaving their estates to one another.

Randy Evans, an attorney for the gay-rights group Forum for Equality, called the ruling "a decision worthy of Solomon."

Legislative backers of the amendment said that although gay marriages were already banned by state law, the amendment was needed to ensure that courts would not authorize such marriages, as occurred in Massachusetts.