T-Mobile USA Inc. asked U.S. regulators in a filing to block Verizon Wireless (NYSE:VZ) from buying two airwaves from cable companies, arguing that the move would pose a clear threat to competition.

New Jersey-based Verizon is seeking two airwaves for $3.6 billion from Comcast Corp. (CMCSA), Time Warner and Bright House Networks LLC, according to Bloomberg. Separately, Verizon purchased a $315 million airwave portion from Cox Communications Inc.

A Verizon spokesman told Bloomberg that the spectrum purchase is in the public interest, and will address the needs of all consumers, putting spectrum to work to meet growing demand.

But Washington-based T-Mobile, a private subsidiary of Germany's Deutsche Telekom AG, said Tuesday in the Federal Communications Commission (FCC) filing the acquisitions would prevent smaller carriers from using the airwaves. It added that it was unlikely that Verizon would use the spectrum for its customers, because it already had an excess supply.

Rather, the principal impact of the acquisition would be to foreclose the possibility that this spectrum could be acquired by smaller competitors -- such as T-Mobile -- who would use it more quickly, more intensively, and more efficiently than Verizon Wireless, T-Mobile said.

T-Mobile was in talks to be acquired by AT&T (NYSE:T) last year, but the deal fell apart amid scrutiny from regulators.