Mpower Communications Finalizes Acquisition of ICG's
                      California Business and Fiber Network

ROCHESTER, NY--JANUARY 3, 2005 -- Mpower Holding Corporation (AMEX: MPE), the
parent company of Mpower Communications Corp., a leading provider of broadband
Internet access and telephone services to business customers, today announced
that it has finalized the acquisition of ICG Communications, Inc.'s California
customer base and network assets.

Mpower has acquired ICG's California retail and wholesale customer segments, its
statewide self-healing SONET fiber network with fully-survivable metropolitan
fiber rings in six major metropolitan markets, and 128 on-net fiber-lit
commercial buildings.

"We fully expect the addition of a wholesale customer base and sales motion and
the expansion of our product portfolio with private line and IP Hosted PBX will
further accelerate Mpower's organic growth capabilities," stated Mpower Chairman
and Chief Executive Officer Rolla P. Huff. "In addition, with a statewide SONET
fiber network complementing our existing deep and dense network of switches and
collocation facilities, we believe Mpower now has the most extensive
facilities-based CLEC network in California. As a result, we believe Mpower is
one of the few CLECs positioned to generate cash by layering revenue streams
onto our network. Given the current regulatory environment, we are taking a
disciplined approach to pursuing additional value creation opportunities by
partnering with ISPs, IXCs and other CLECs."

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 private line, data, telephony, Internet access and Web
hosting services for business customers and carriers. Further information about
the company can be found at www.mpowercom.com http://www.mpowercom.com.


Forward-Looking Statements
Under the safe harbor provisions of the Private Securities Litigation Reform Act
of 1995, Mpower cautions investors that certain statements contained in this
press release that state our and/or management's intentions, hopes, beliefs,
expectations or predictions of the future are forward-looking statements.
Management wishes to caution the reader that these forward-looking statements
are not historical facts and are only estimates or predictions. Actual results,
including projections with respect to Mpower's future operating performance and
the revenues and operating income generated by the business acquired from ICG
may differ materially from those projected as a result of risks and
uncertainties including, but not limited to, our ability to retain ICG customers
and to increase revenues from the acquired ICG business, our ability to
effectively integrate the ICG business into our operations, unexpected costs of
integrating the ICG business into our operations, future sales growth, changes
in federal or state telecommunications regulations, market acceptance of our
product and service offerings, the liquidity of our common stock, our ability to
secure adequate financing or equity capital to fund our operations and network
expansion, our ability to manage growth and maintain a high level of customer
service, the performance of our network and equipment, our ability to enter into
strategic alliances or transactions, the cooperation of incumbent local exchange
carriers in provisioning lines and interconnecting our equipment, regulatory
approval processes, the effect of regulatory decisions on our access charges and
operating costs, changes in technology, price competition and other market
conditions and risks detailed from time to time in our filings with the
Securities and Exchange Commission. We undertake no obligation to update
publicly any forward-looking statements, whether as a result of future events,
new information, or otherwise.