Rockwood Holdings, Inc. (NYSE: ROC) announced today it entered into a definitive agreement to sell its Clay Based Additives business to ALTANA Group, a German based global specialty chemical company for a purchase price of $635 million, subject to customary adjustments. A segment of Rockwood’s Performance Additives business, Clay Based Additives had 2012 sales of $191.4 million. This transaction is expected to close during the fourth quarter 2013 following receipt of certain regulatory approvals. “The sale of Clay Based Additives is another step forward in the implementation of our long term business strategy to maximize shareholder value,” said Seifi Ghasemi, Chairman and Chief Executive Officer. “I want to thank our Clay Based Additives management team and employees for their dedication and execution over the past few years during a challenging macro-environment. We wish them well as they work with ALTANA to develop and grow their business platform.” Lazard acted as Rockwood’s financial advisor and Hughes Hubbard & Reed LLP and Willkie Farr & Gallagher LLP as legal advisors. Clay Based Additives The Clay Based Additives segment develops and manufactures a range of specialty rheology modifiers and additives. These products are used in a wide variety of applications to modify viscosity, thickness and flow characteristics, and keep solids in suspension. End products in which these additives are used include industrial and architectural coatings, oil and gas drilling fluids, consumer and household care products, and inks, paper and composites. It had net sales of $191.4 million, $202.3 million and $169.6 million for the years ended December 31, 2012, 2011 and 2010, respectively. ALTANA Group The ALTANA Group, headquartered in Wesel, Germany, is a global company with sales of more than EUR 1.7 billion. ALTANA develops and produces high-quality, innovative products in the specialty chemicals business with the matching specialty products for coating manufacturers, paint and plastics processors, the printing and cosmetic industries, and the electrical and electronics industry. ALTANA has 42 production facilities, over 50 service and research laboratories and about 5,360 employees worldwide.