Rockwood Holdings, Inc. (NYSE: ROC) (the “Company”) announced today that funds affiliated with Kohlberg Kravis Roberts & Co. L.P. have agreed to sell 6,900,838 shares of their common stock in an underwritten offering. The Company will not receive any proceeds from the offering. The shares will be offered pursuant to an automatically effective registration statement previously filed with the Securities and Exchange Commission. A prospectus supplement relating to the offering will be filed with the Securities and Exchange Commission. Morgan Stanley & Co. LLC is serving as sole book running manager of the offering. Morgan Stanley & Co. LLC proposes to offer the shares of common stock obtained from the selling stockholders from time to time for sale in one or more transactions on the NYSE, in the over-the-counter market, through negotiated transactions or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices. Copies of the U.S. prospectus related to the Offering may be obtained by contacting Morgan Stanley & Co. LLC, 180 Varick Street, 2nd Floor, New York, New York 10014 Attention: Prospectus Department (telephone 866-718-1649 (toll free) or 917-606-8474) or by e-mailing firstname.lastname@example.org). 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. Rockwood Holdings, Inc. is a leading global specialty chemicals and advanced materials company. Rockwood Holdings, Inc. and its subsidiaries and affiliates (“Rockwood”) has a worldwide employee base of approximately 10,300 people and annual net sales of approximately $3.7 billion. Rockwood focuses on global niche segments of the specialty chemicals, pigments and additives and advanced materials markets.