WASHINGTON, D.C., August 12, 2004 - Cogent Communications Group, Inc. (AMEX: COI), a multinational Tier One, optical Internet service provider, announced today that it has acquired a majority of the assets of Unlimited Fiber Optics, an ISP based out of San Francisco. Included in the assets are UFO's customer base and network. UFO's customer base is comprised of data service customers and its network is comprised of fiber optic facilities located in San Francisco, Los Angeles and Chicago.

Cogent plans to migrate the customers onto Cogent's Tier 1 facilities based backbone over the next 90 days. Most of UFO's points of presence are located in buildings in which Cogent already has a presence which should make the transition easier and more cost effective to accomplish.

Cogent plans to use this acquisition to further augment its Point-to-Point Layer 2 Transport services announced earlier this year in cities including Chicago, Dallas, New York, Washington, D.C. and San Francisco.

This marks Cogent's fourth acquisition this year and 10th acquisition overall. Financial Terms are not disclosed.

About Cogent Communications

Cogent is a facilities-based provider of low-cost, high-speed Internet access and Internet Protocol, or IP, connectivity in North America and Europe. Cogent Communications' global headquarters is located at 1015 31st Street, NW, Washington, D.C. 20007.

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Information in this release may involve expectations, beliefs, plans, intentions or strategies regarding the future. These forward-looking statements involve risks and uncertainties. All forward-looking statements included in this release are based upon information available to Cogent Communications Group, Inc. as of the date of the release, and we assume no obligation to update any such forward-looking statement. The statements in this release are not guarantees of future performance and actual results could differ materially from our current expectations. Numerous factors could cause or contribute to such differences. Some of the factors and risks associated with our business are discussed in Cogent's registration statements filed with the Securities and Exchange Commission and in its other reports filed from time to time with the SEC.

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