Houston-based Quanta Services turned to Duane Morris for the pending sale of its fiber optic licensing operations to Crown Castle International Corp. for about $1 billion in cash.

Crown Castle, also based in Houston, is using a team from Cravath, Swaine & Moore.

On April 30, Quanta announced a definitive agreement to sell Quanta Fiber Networks, known as Sunesys, to Crown Castle. Sunesys, a wholly owned subsidiary of Quanta, is a fiber services provider that owns or has rights to nearly 10,000 miles of fiber in major metropolitan markets. The transaction is subject to regulatory approvals and other customary closing conditions, but is expected to close by year end.