U.S. Cellular today announced it will sell 595 towers to Vertical Bridge Holdings, LLC for $159 million. The companies expect to close the transaction in early 2015.

“We will use the proceeds from the sale of these non-strategic assets to invest in other long-term investments that position U.S. Cellular for future growth opportunities,” U.S. Cellular President and CEO Kenneth R. Meyers said in a statement.

The towers are located in “large metropolitan markets” and Vertical Bridge said many of the site locations would be difficult to replace.

Vertical Bridge leases its sites to AT&T, Cellular One, Clear, Cricket, MetroPCS, Sprint, T-Mobile and Verizon. The company also leases to federal, state and local government agencies, broadcasters, paging companies, back-haul providers, LMR-SMR operators.

Along with the sale of part of its tower portfolio, U.S. Cellular is also currently pursuing a spectrum swap with AT&T. First spotted by Phone Scoop, an FCC filing details the transaction involving AT&T and U.S. Cellular trading PCS airwaves. AT&T would receive 10 to 20 megahertz of Broadband PCS spectrum in 104 counties covering all or parts of 32 CMAs. U.S. Cellular would receive 10 to 15 megahertz of Broadband PCS spectrum in 18 counties covering all or parts of seven CMAs.