WASHINGTON — President Obama is expected to announce as soon as Tuesday that he will use his executive authority to permanently ban new offshore drilling in parts of federally owned waters off the Atlantic coast and in the Arctic Ocean, according to people familiar with the decision.

Mr. Obama, who is searching for ways to bolster his environmental legacy in the last days of his administration, is expected to use a provision in the 1953 Outer Continental Shelf Lands Act to ban the drilling, according to those people, who spoke on the condition of anonymity because plans for the announcement were not yet final.

The 1953 law, which governs how the executive branch uses and leases federal waters for offshore energy exploration, includes a provision that allows presidents to put those waters off-limits to oil and gas drilling. Presidents Dwight D. Eisenhower, Richard M. Nixon and Bill Clinton used the law to protect sections of the Atlantic, Pacific and Arctic Oceans, but those protections came with time limits, usually one to two decades.

It is possible that Mr. Obama could use the law to try to permanently protect far wider areas from drilling, said people familiar with his plans, but they stressed that his plans were not yet final.