WASHINGTON, D.C., May 18, 2004 - Cogent Communications (AMEX: COI), a facilities-based provider of high speed Internet access and Internet Protocol connectivity, today announced that it filed a registration statement with the Securities and Exchange Commission for the proposed public offering of $75.0 million of its common stock.

In connection with the offering, subject to stockholder approval, Cogent's outstanding preferred stock will be converted into 500.2 million shares of common stock and Cogent will effect a 1-for-20 reverse stock split of its 514.3 million shares of outstanding common stock (which includes the common stock issued upon conversion of the preferred stock). This will result in 25.7 million shares of common stock outstanding prior to the offering.

The offering will be made through an underwriting syndicate led by Jefferies & Company, Inc. as sole book-runner. CIBC World Markets and Friedman Billings Ramsey will act as co-managers.

The price of the common stock to be sold in the offering will be negotiated between Cogent and Jefferies & Company, Inc. on behalf of the underwriters, taking into account the reverse stock split, the conversion of the preferred stock, prevailing market conditions, Cogent's historical performance and estimates of Cogent's business and earnings potential.

A registration statement relating to these securities has been filed with the Securities and Exchange Commission but has not yet become effective. These securities may not be sold nor may offers to buy be accepted prior to the time the 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.

The Company will file a prospectus relating to the offering with the SEC and will be available on the SEC's website at www.sec.gov and on the Company's website at www.cogentco.com.

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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