Zayo, a leading communications infrastructure provider backed by DigitalBridge and EQT, announced it has entered into a definitive agreement to acquire Crown Castle’s Fiber Solutions business in a transaction valuing the business at approximately $4.25 billion.

Crown Castle (NYSE:CCI) will sell all of its fiber segment in two transactions to an EQT fund and Zayo Group Holdings for a total of $8.5B and use the proceeds to repay debt and to buy back stock, the company said on Thursday.

Zayo said the purchase will expand its fiber network and reinforce its strategic focus on enabling AI and digital transformation across the U.S.