The Bush administration violated the law when it dropped efforts to bring back gray wolves in the Northeast, a federal judge in Vermont ruled yesterday.

A coalition of environmental groups had challenged the 2003 decision to reduce Endangered Species Act protection for gray wolves across the lower 48 states; while the species has rebounded in the Great Lakes and Northern Rockies, gray wolves are almost nonexistent in the Northeast.

In his ruling, U.S. District Judge J. Garvan Murtha noted that the U.S. Fish and Wildlife Service said there would be " 'extensive and significant gaps' in the wolf's range without a wolf population in the Northeast."

Larry J. Schweiger, president of the National Wildlife Federation, said the ruling means the Interior Department will have to revisit its decision to downgrade the wolves' status from endangered to threatened.

"The wildlife legacy we are striving to leave our children in New England can now include one of the most majestic of all species," Schweiger said.

Interior Department spokesman Hugh Vickery said the administration, which lost a similar case this year involving the struggling gray wolf population in the Pacific Northwest, was reviewing the decision and had not decided whether to appeal.