NEW YORK, Sept. 8 -- ICG Communications Inc., a regional phone company based in Englewood, Colo., has announced the planned sale of its fiber-optic networking unit. In this latest in a series of asset disposals by the telecom, ICG will sell its Fiber Optic Technologies Inc. unit, which provides network integration and support services, to ACS Communications Inc. Terms of the sale were not disclosed. ICG will retain its Telecom unit, which offers local telephone service in Colorado, California, the Ohio Valley and parts of the southeastern US.This transaction follows last month's sale of two ICG units, ICG Satellite Services Inc. and Maritime Telecommunications Network Inc., to Boston-based American Tower Corp. for $100 million. Included in the sale to American Tower were a global maritime telecommunications network serving cruise ship passengers and a teleport in Holmdel, N.J., that transmits voice, video and Internet data by satellite. Earlier this year ICG sold a major portion of its NetCom unit to Internet service provider MindSpring Enterprises Inc. of Atlanta in a deal valued at $245 million. ICG retained NetCom's network assets, as well as its accounts in the UK, Canada and Brazil.