WASHINGTON, D.C., May 10, 2006 - Cogent Communications Group, Inc. (NASDAQ: CCOI) announced today that it plans to sell 12 million shares of its common stock in an underwritten public offering. The offering will consist of 4 million shares sold by the company and 8 million shares sold by selling stockholders. The shares sold by the selling shareholders represent approximately 25% of the shares held by Cogent's major investors. The Company plans to initiate the offering by the end of May 2006.

Dave Schaeffer, Cogent's Chief Executive Officer, said that the offering would serve two purposes. "First, it increases the amount of Cogent's common stock available in the public markets, making the common stock more liquid. Second, it provides additional capital for Cogent to pursue its growth strategies, including adding sales force and additional buildings to its network."

These securities may not be sold nor may offers to buy be accepted prior to the time a supplemental registration statement becomes effective. This press release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

About Cogent Communications

Cogent Communications (NASDAQ: CCOI) is a multinational Tier 1 facilities-based ISP. Cogent specializes in providing businesses with high speed Internet access and point-to-point transport services. Cogent's, all-optical IP network backbone spans 14 countries and provides IP services in over 95 markets located in North America and Europe.

Cogent Communications is headquartered at 1015 31st Street, NW, Washington, D.C. 20007. For more information, visit www.cogentco.com. Cogent Communications can be reached in the United States at (202) 295-4200 or via email at Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser..

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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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