T-Mobile USA, the No. 4 U.S. mobile provider, has negotiated a $250 million (154 million pounds) break-up fee should a deal to sell its wireless broadcast towers to Crown Castle International Corp fall through, according to a regulatory filing with the U.S. Securities and Exchange Commission.

T-Mobile USA is selling the rights to operate 7,200 of its wireless broadcast towers for $2.4 billion to Crown Castle to help fund a network upgrade and reduce debt at its parent Deutsche Telekom AG.

Crown Castle has the option to pay another $2.4 billion to buy the towers outright from T-Mobile USA at the end of the lease term for each tower - between 2025 and 2048 - under the deal announced on Friday.

The deal is expected to close in the fourth quarter, according to the companies.

(Reporting by Nicola Leske; Editing by Gerald E. McCormick)