Atlantic Tele-Network Inc., a Beverly company that provides telecommunications services to various rural and under-served markets, said Tuesday that it has agreed to sell a domestic retail wireless businesses in its portfolio to AT&T for about $780 million.

That retail business operates under the name of Alltel and serves customers in Georgia, North Carolina, South Carolina, Illinois, Ohio, and Idaho. AT&T will purchase Alltel’s operations in an all-cash transaction, Atlantic Tele-Network said in a press release.