The Louisiana Supreme Court (search) on Wednesday unanimously reinstated the anti-gay marriage amendment to the state constitution that was overwhelmingly approved by voters in September.

The high court reversed a state district judge's ruling in October striking down the amendment on the grounds that it violated a provision of the state constitution requiring that an amendment cover only one subject.

"Each provision of the amendment is germane to the single object of defense of marriage and constitutes an element of the plan advanced to achieve this object," the high court said.

The court's ruling puts the amendment in the constitution.

"We're obviously delighted," said attorney Michael Johnson, who represented the Alliance Defense Fund (search), which argued for the amendment's legality before the Supreme Court.

The Louisiana Gay and Lesbian Political Action Coalition (search) said a statement would be released shortly.

The amendment was sent to the ballot by the Legislature and approved by 78 percent of the voters on Sept. 18.

Legislative backers said that although gay marriages are banned by state law, the amendment was needed to ensure that courts would not authorize the marriages, as had happened in Massachusetts.

In striking down the "defense of marriage" amendment, Judge William Morvant of Baton Rouge had ruled that the amendment also prevented the state from recognizing any legal status for common-law relationships, domestic partnerships and civil unions between both gay and heterosexual couples.

Six of the justices joined in the majority opinion authored by Justice Jeanette Theriot Knoll. The seventh, Chief Justice Pascal Calogero, wrote a concurring opinion.

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

Opponents had warned that the amendment went far beyond banning gay marriage and would deny contractual rights to all unmarried couples — whether gay or heterosexual — in such areas as owning property, willing it to heirs, and taking legal care of an incapacitated partner. As a result, they contended, the amendment had more than one object, and therefore could not become part of the constitution.

But the Supreme Court said the each part of the amendment is "germane to the object of `defense of marriage.'"

Eleven other states adopted similar amendments in the fall elections. President George Bush also has proposed a federal anti-gay marriage amendment.