Leap Wireless International Inc is opposing AT&T Inc's planned $39 billion acquisition of T-Mobile USA on the grounds that it would harm consumers.

Leap said on Tuesday that the elimination of T-Mobile USA, a Deutsche Telekom AG unit, as a competitor would accelerate a trend toward alarming concentration in the wireless industry around the two biggest companies.

Another rival, MetroPCS Communications Inc

, had suggested that if regulators let the deal go ahead, AT&T should be forced to divest some assets.

Sprint Nextel Corp , the No. 3 U.S. mobile provider, has been the most vociferous opponent to the merger, which would make No. 2 U.S. mobile provider AT&T the biggest U.S. operator, ahead of current leader Verizon Wireless.

Verizon Wireless is a venture of Verizon Communications Inc and Vodafone Group Plc .

(Reporting by Sinead Carew; editing by Gerald E. McCormick)