International Securities Exchange, Inc. Plans Initial Public Offering

The International Securities Exchange, Inc. (ISE) announced today that it plans to issue shares of its common stock in an underwritten initial public offering. The offering is expected to commence in the second half of 2004, subject to Securities and Exchange Commission (SEC) effectiveness and the receipt of all necessary approvals.

This announcement shall not constitute an offer to sell or the solicitation of an offer to buy any securities described herein, nor shall there be any sale of these securities in any state or jurisdiction in which the offer, solicitation or sale would be unlawful. This announcement is being issued pursuant to and in accordance with Rule 135 under the Securities Act of 1933.