LINCOLN, Neb. —  A federal judge Thursday struck down Nebraska's ban on gay marriage (search), saying the measure interferes not only with the rights of gay couples but also with those of foster parents, adopted children and people in a host of other living arrangements.

The constitutional amendment, which defined marriage as a union between a man and a woman, was passed overwhelmingly by the voters in November 2000.

U.S. District Judge Joseph Bataillon (search) said the ban "imposes significant burdens on both the expressive and intimate associational rights" of gays "and creates a significant barrier to the plaintiffs' right to petition or to participate in the political process."

Bataillon said the ban beyond "goes far beyond merely defining marriage as between a man and a woman."

The judge said the "broad proscriptions could also interfere with or prevent arrangements between potential adoptive or foster parents and children, related persons living together, and people sharing custody of children as well as gay individuals."

Forty states have laws barring same-sex marriages, but Nebraska's ban went further, prohibiting same-sex couples from enjoying many of the legal protections that heterosexual couples enjoy. Gays and lesbians who work for the state or the University of Nebraska (search) system, for example, were banned from sharing health insurance and other benefits with their partners.

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Nebraska has no state law against gay marriage, but state Attorney General Jon Bruning said same-sex marriages were not allowed before the ban and would not be permitted now.

Bruning said he will appeal the ruling.

"Seventy percent of Nebraskans voted for the amendment to define marriage as a union between one man and one woman, and I believe that the citizens of this state have a right to structure their constitution as they see fit," Bruning said.

The challenge was filed by the gay rights organization Lambda Legal and the ACLU's Lesbian and Gay Project.

Lamba Legal attorney David Buckel has called the ban "the most extreme anti-gay family law in the entire nation."

Carla Petersen, a member of Metropolitan Community Church in Omaha, which advocates for gay rights, hailed the ruling.

"Every step is a good step," Petersen said. "It really will get the ball rolling again."

The ruling did not surprise the executive director of the Nebraska Family Council, which led the petition drive to get the ban on the ballot. Al Riskowski said the decision will renew the call to pass a constitutional amendment defining marriage as only between a man and a woman.

Massachusetts has allowed gay marriage since last May. Vermont has offered civil unions to gays since 2000; Connecticut will begin offering civil unions in October.