SAN ANTONIO (WiMAX Day). US telecoms operator AT&T announced yesterday that it will sell its 2.5 GHz spectrum to Clearwire for US$ 300 million. The sale is being made to satisfy regulatory conditions for the merger with BellSouth that was approved by the US Federal Communications Commission (FCC) in December 2006. Prior to gaining FCC approval, Clearwire was one of several companies that had petitioned the FCC that AT&T should be required to divest of its spectrum.