SACRAMENTO

The Pacific fisher, a rare relative of weasels, otters and minks that lives in old-growth forests in California, Oregon and Washington, is a threatened species but there isn't money to offer increased protections at this time, the U.S. Fish and Wildlife Service ruled Thursday.

The fisher will become a "candidate" for listing as threatened or endangered under the federal Endangered Species Act as efforts are concentrated on other species at greater immediate risk, announced Steve Thompson, manager of the service's California-Nevada office in Sacramento.

Its status will be reviewed annually until it is either added to the list or the population recovers to the point protections are no longer needed. However, environmental groups said they will sue to force an immediate listing.

The decision follows a year of study ordered after a federal judge found the service missed earlier legal deadlines by more than two years.

Environmental groups were pleased the service concluded the species is in trouble and that the service found the Western population is distinct from fisher populations elsewhere in the nation, but critical of the decision not to add protections.

"They're acknowledging the species is going extinct, but they're not going to do anything about it because they don't have the resources," said Greg Loarie, an attorney with Earthjustice who represented 19 groups including the Center for Biological Diversity and Sierra Nevada Forest Protection Campaign. "Fishers need protection now."

The groups allege the Bush administration is violating the act because it is making little progress in aiding endangered species, and will sue again to force an immediate listing. The administration says its hands are tied by a lack of money and endless environmental lawsuits that now drive policies and protection efforts.

When it comes to the fisher, the groups also criticized the administration for proposing to increase logging of larger trees in Sierra Nevada and Northwest national forests. The administration says forest thinning is needed to prevent devastating wildfires that would do even more severe damage to the fisher's old growth habitat.

The fisher once lived in ancient forests from the Sierra Nevada north through western Oregon and Washington.

But trapping and habitat loss have reduced the species to three known populations, the service found: one in the Siskiyou, Klamath, and Trinity ranges in northwestern California and southern Oregon, another in the southern Sierra Nevada, and a reintroduced population in the Cascades in southern Oregon.

The fisher is extinct or reduced to scattered individuals in Washington, the service said.