Starting in March, residents in counties on the Eastern Shore and in central Maryland requesting new phone numbers may receive a new area code, state utility regulators announced Wednesday.

The new area code, 667, is being activated because the Federal Communications Commission expects the existing 410 and 443 codes will be exhausted in early 2012, said Douglas Nazarian, chairman of the Maryland Public Service Commission.

It will be issued in the areas where 410 and 443 are currently used: the city of Baltimore as well as Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil, Dorchester, Harford, Howard, Kent, Queen Anne's, Somerset, Talbot, Wicomico and Worcester counties, according to the commission.

The new area code will permit an additional 8 million numbers, Nazarian said.

Phone companies request blocks of the numbers in advance, and only about 17,000 to 19,000 410 and 443 numbers still remain after a run on the numbers in September, Nazarian said at a news conference Wednesday.

Usually, the activation process starts about 10 months before the new number becomes available, but the spike in demand has forced a stepped up pace, Nazarian said.

He said the commission did not expect any problems with this rollout. As a signal of the boom in technology such as modems and fax machines that relied on phone numbers, Maryland added the 240 and 443 area codes in 1997. They came just five years after activation of the 410 area code.

Establishing 443 and 240 required training Marylanders to dial 10 digits instead of seven. It also required a lot of behind-the-scenes network improvements.

"That groundwork has already been laid," Nazarian said.

Although there are 10 thousand possible combinations between 000 and 999, the number of available options are more limited. Obviously, many are already assigned to geographic areas, and others, such as 800 and 888, are reserved for toll-free numbers. Some have been reserved for emergency use or other purposes, Nazarian said.

Customers with existing 410 or 443 numbers would still be able to keep those numbers if they move to a new cell phone company, he said.