Mexico's telecoms regulator on Thursday said it had approved swaps of frequency blocks and a spectrum rental deal between AT&T Inc and Telefonica SA, the main competitors to the country's dominant player, Carlos Slim's America Movil. The Federal Telecommunications Institute said it had authorized the swaps and the rental deal that would allow AT&T to use spectrum in the range of frequencies in the 1.7/2.1 GHz band in some regions, and for Telefonica's local unit to use it in the frequency ranges of the 1.9 GHz band.