The public will have 30 more days to comment on federal regulations for exploratory drilling in the Arctic.

The Bureau of Ocean Energy Management and the Bureau of Safety and Environmental Enforcement announced Thursday they're extending the comment period.

The regulations would apply only to the Chukchi (chuk-CHEE') and Beaufort (BOH'-fort) seas off Alaska's northwest and north coast.

The rules would not apply to exploratory drilling this summer by Royal Dutch Shell PLC in the Chukchi. However, the company's preparations for drilling were considered in the proposed regulations.

The rules would require companies to be able to drill a relief well to contain an uncontrolled spill before ice sets in.

Conservation groups contend Arctic drilling can't be done safely.

The 30-day extension will end May 27.