SPRINGDALE, Ark. (AP) _ Callers dialing long-distance to telephone numbers in northwestern Arkansas can begin using the new 479 area code on Jan. 19 _ and they must use it starting six months later.


The new area code has been assigned to part of the section of Arkansas now covered by the 501 area code, which telephone regulators say would run out of telephone numbers within a year unless it is split.


The new 479 area covers all of booming northwestern Arkansas, including the cities of Rogers, Bentonville, Springdale, Fayetteville, Fort Smith and Russellville.


Phone companies will phase in the new number through the spring and early summer to allow customers time to become used to the new numbers and to allow businesses, schools and governments time to change the phone numbers on their letterheads and business documents.


Some of the area's biggest companies _ including Wal-Mart Stores Inc. and Tyson Foods Inc. as well as the University of Arkansas campus at Fayetteville _ will be affected by the change.


Calls into the region can be made with either the current 501 area code or the new 479 area code until July 20. But beginning on that day, all calls into the area must be prefaced with the 479 code, or the call will not be completed.


Arkansas had only one area code, 501, for decades until it was split into two areas _ 501 and 870 _ only four years ago, in 1997.


According to information from Southwestern Bell, in recent years the combination of new technology, increased consumer demand, and the opening of local telephone markets to competition has strained existing telephone-number resources. Every new telephone, pager, fax machine, cellular phone and computer modem has chipped away at the existing supply of numbers.


The state Public Service Commission said the 501 area code would have been exhausted during the fourth quarter of 2002.


Areas around Little Rock and Hot Springs will keep the 501 area code, and northern, eastern and southern Arkansas will still be covered by the 870 designation. The supply of numbers in the 870 area code is projected to be adequate until late 2006.