ROCHESTER, NY -- JULY 15, 2004 -- Mpower Communications Corp., a leading provider of broadband Internet access and telephone services to business customers, applauded yesterday’s decision by the U.S. Ninth Circuit Court of Appeals that overturned a ruling by the California Public Utilities Commission (CPUC) district court with respect to the costs that Pacific Bell’s competitors must pay for access to Pacific Bell’s network.

Essentially, the Court of Appeals found that the methodology used by the CPUC improperly allocated too large a share of PacBell’s common costs to CLECs for access to PacBell’s local telephone network.

“Mpower has always been a facilities-based CLEC with a deep network built into the switches and end offices of the incumbent. We believe the foundation of true competition lies in making UNE loops cost-effectively available to competitors that have invested in their own infrastructure,” commented Mpower Communications Chairman and Chief Executive Officer Rolla P. Huff.

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.

Forward-Looking Statements

Under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, certain statements contained in this press release regarding our and/or management’s intentions, hopes, beliefs, expectations or predictions of the future are forward-looking statements. These forward-looking statements are not historical facts and are only estimates or predictions. Actual results may differ materially from those projected as a result of risks and uncertainties including, but not limited to, 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.