ANCHORAGE, Alaska (AP) – Three conservation groups have reached a partial settlement with the federal government on polar bear habitat that could add restrictions to future petroleum exploration or drilling off Alaska’s coast.

The agreement filed Monday sets deadlines for the Interior Department secretary to designate “critical habitat” for polar bears.

Such a designation prohibits federal agencies from taking actions that may “adversely modify” critical habitat that could interfere with polar bear recovery.

Those actions might include offshore petroleum exploration or drilling, said Kassie Siegel, an attorney for the Center for Biological Diversity.

A spokesman for the U.S. Fish and Wildlife Service in Anchorage had no immediately comment on the settlement filed in U.S. District Court in Oakland, Calif.

The lawsuit was filed in March after Interior Secretary Dirk Kempthorne missed the deadline for declaring polar bears threatened or endangered under the Endangered Species Act.

Kempthorne declared them “threatened,” or “likely to become endangered,” on May 14, citing polar bears’ need for sea ice, the dramatic loss of sea ice in recent decades and computer models that suggest sea ice is likely to further recede in the future.

Siegel said in most cases, critical habitat is supposed to be designated at the same time a species is listed as threatened or endangered. Her group, the Natural Resources Defense Council and Greenpeace sued to force a designation.

Under the settlement, a proposed critical habitat rule will be issued next year, and will be subject to public comment and public hearings, Siegel said.

The agreement sets a deadline of June 30, 2010, for a final rule designating critical habitat for the polar bear.

According to the groups, the settlement Monday does not address their claim that Kempthorne violated the Endangered Species Act by listing the polar bear as “threatened” rather than “endangered.”

They also claim he violated the law by issuing a special rule exempting polar bears from protections otherwise provided by the Endangered Species Act.

The groups said the case is expected to be heard early next year in federal district court in Oakland.

Five separate lawsuits have been filed in Washington, D.C., to overturn the listing of polar bears as threatened.

One was filed by the state of Alaska on orders of Gov. Sarah Palin, the Republican vice presidential candidate.

AP-ES-10-06-08 1744EDT