T-Mobile US (TMUS -0.08%) has agreed to purchase 10 MHz of Advanced Wireless Services spectrum from U.S. Cellular (USM -1.63%) for $308 million, T-Mobile announced today.

That AWS spectrum can serve 32 million people in the Mississippi Valley region. The 29 markets covered include St. Louis, Nashville, Kansas City, Memphis, Lexington, Little Rock-North Little Rock, Birmingham, New Orleans, and Louisville.

"This is a rare opportunity to secure precious AWS spectrum in key markets that will immediately be put to use by both T-Mobile and MetroPCS customers," said T-Mobile CEO John Legere. The deal still needs approval from the Federal Communications Commission and Justice Department. The companies expect the transaction to close in the fourth quarter.

T-Mobile recently merged with MetroPCS to create publicly held T-Mobile US. Before the merger, the previously named T-Mobile USA was a private company held by German company Deutsche Telekom. Deutsche Telekom  holds 74% of the newly formed company.

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