T-Mobile has agreed to pay Verizon Wireless an undisclosed cash sum as part of a deal that allows the two to swap wireless spectrum and acquire additional depth to expand 4G capacity in specific markets.

The spectrum includes some that will be purchased by Verizon Wireless, which is joint owned by Vodafone (NYSE:VOD) and Verizon Communications (NYSE:VZ), in pending transactions with Cox, Leap and SpectrumCo, a consortium of cable companies including Comcast (NASDAQ:CMCSA) and Time Warner (NYSE:TWC).

Verizon's deal with T-Mobile is contingent on the close of those deals, as well as on approval by the Federal Communications Commission, which is expected to make a decision later this summer.

The private commercial agreement includes a number of intra-market spectrum swaps that the companies say will enable better use of the advanced wireless services band. The deal comes as T-Mobile plans to roll out an LTE data network by the end of 2013.