This undated file photo from the U.S. Fish and Wildlife Service's Alaska Image Library shows a polar bear. Less than a month after declaring polar bears a threatened species because of global warming, the Bush administration is giving oil companies permission to annoy and potentially harm them in the pursuit of oil and natural gas.

Washington ? Less than a month after declaring polar bears a threatened species because of global warming, the Bush administration is giving oil companies permission to annoy and potentially harm them in the pursuit of oil and natural gas.

The Fish and Wildlife Service issued regulations this week providing legal protection to seven oil companies planning to search for oil and gas in the Chukchi Sea off the northwestern coast of Alaska if “small numbers” of polar bears or Pacific walruses are incidentally harmed by their activities over the next five years.

Environmentalists said the new regulations give oil companies a blank check to harass the polar bear.

About 2,000 of the 25,000 polar bears in the Arctic live in and around the Chukchi Sea, where the government in February auctioned off oil leases to ConocoPhillips Co., Shell Oil Co. and five other companies for $2.6 billion. Over objections from environmentalists and members of Congress, the sale occurred before the bear was classified as threatened in May.

Polar bears are naturally curious creatures and sensitive to changes in their environment. Vibrations, noises, unusual scents and the presence of industrial equipment can disrupt their quest for prey and their efforts to raise their young in snow dens.

However, the Fish and Wildlife Service said oil and gas exploration will have a negligible effect on the bears’ population.

“The oil and gas industry in operating under the kind of rules they have operated under for 15 years has not been a threat to the species,” H. Dale Hall, the Fish and Wildlife Service’s director, told The Associated Press on Friday. “It was the ice melting and the habitat going away that was a threat to the species over everything else.”

The agency made no secret that oil and gas operations would continue in polar bear territory when it announced May 14 that melting sea ice threatened the creature’s survival. But Interior Secretary Dirk Kempthorne assured the public that the bear population would not be harmed.

“Polar bears are already protected under the Marine Mammal Protection Act, which has more stringent protections for polar bears than the Endangered Species Act does,” Kempthorne said.

Environmentalists already suing the agency over its determination that the bear’s threatened status cannot be used to regulate global warming gases said Kempthorne’s earlier assurances were misleading.

“Now, three weeks later, Interior issues a rule under the act that we view as a blank check to harass the polar bear in the Chukchi Sea,” said Brendan Cummings, oceans program director at the Center for Biological Diversity. He added that his group believes the new regulations are illegal.

Exploring in the Chukchi Sea’s 29.7 million acres will require as many as five drill ships, one or two icebreakers, a barge, a tug and two helicopter flights per day, according to the government. Oil companies will also be making hundred of miles of ice roads and trails along the coastline.

“We are poorly equipped to address those risks and challenges,” said Steven Amstrup, one of the foremost experts on polar bears and a scientist at the U.S. Geological Survey’s Alaska Science Center. “To assess what the impacts are going to be, we should know more about the bears.”