Louisville, Colorado-based Zayo Group, a provider of bandwidth and telecom services, said Thursday afternoon that it has signed a definitive agreement to acquire Citynet Fiber Network (CFN), a Tulsa, Oklahoma unit of Citynet. According to Zayo, this is the firm's sixth acquisition since May. Financial terms of the acquisition were not disclosed. CFN will become part of Zayo's fiber based bandwidth unit, Zayo Bandwidth. Zayo said that CFN has more than 8,500 miles of fiber covering 57 markets in 10 states.