Englewood, Colo., October 22, 2004 – ICG Communications, Inc. announced today that it has signed a definitive agreement for the sale of ICG customers and certain network operating assets in California to Mpower Holding Corporation (AMEX: MPE).

Under the terms of the sale, Mpower will issue 10,740,030 shares of Mpower Holding Corporation common stock and 2,000,000 warrants with a strike price of $1.383 to ICG. Additionally, Mpower will assume certain ICG leases in California, including long-term fiber capital leases. The transaction is expected to close by the end of this year, subject to regulatory approval.

“ICG’s customers will benefit from this transaction,” said Dan Caruso, president and chief executive officer of ICG. “As a result of the combination of ICG’s California business with Mpower’s business, ICG’s California customers will be served by a supplier that is strong financially, has an extensive California network, and offers a broad range of Internet, data, and voice services. Likewise, customers in ICG’s remaining markets benefit from having a financially strong and geographically-focused service provider. “

Under the terms of the Agreement, Mpower will immediately assume management control of ICG’s retail and wholesale California customer base and network assets. Until the transaction closes, ICG and Mpower will jointly serve the California customers to preserve high levels of customer service and support and to ensure a seamless transition for customers and vendors.

"The decision to sell our California market is consistent with our strategy to focus on our core regional assets and VoIP services," added Dan Caruso. As part of the transaction, Mpower will sell QoS-based IP Centrex services through ICG’s industry-leading VoicePipe™ product. ICG will continue to operate the VoicePipe platform and will support both Mpower and ICG’s remaining CLEC properties.

About ICG
ICG Communications, Inc. is a premiere business communications company that specializes in converged voice and data services. ICG has a national footprint and extensive metropolitan fiber. ICG products and services include, voice and Internet Protocol (IP) solutions including VoicePipe™, voice services, dedicated Internet access (DIA), and private line transport services. ICG provides corporate customers and other carriers with flexible and reliable solutions. For more information about ICG Communications, visit the company's Web site at www.icgcomm.com.

About Mpower Holding Corporation
Mpower Holding Corporation (AMEX: MPE) is the parent company of Mpower Communications, a leading facilities-based broadband communications provider offering a full range of data, telephony, Internet access and Web hosting services for small and medium-size business customers. Further information about the company can be found at www.mpowercom.com.