Over a four-year-period, AT&T operated many point-to-point microwave stations throughout the United States at variance with its licenses, the FCC said in a statement announcing the agreement.

Wireless stations are used by phone companies to connect calls and television signals directly between towers in areas that cannot be connected using standard wireline or fiber optic cable because of cost or terrain.

AT&T said in a statement that "minor discrepancies" were discovered as a result of a review of recently acquired licenses. "None of them had any impact on consumers or other carriers," the company said, adding that the agreement resolved a fine first proposed by the FCC in January 2015.

(Reporting by David Shepardson; Editing by Chizu Nomiyama and Paul Simao)