CCMP CMC Materials Inc

The last sentence of the first graph should be disregarded. There will not be a webcast of the presentation. The corrected release reads: CABOT MICROELECTRONICS TO PRESENT AT THE SIDOTI & COMPANY ANNUAL WEST COAST INSTITUTIONAL INVESTOR FORUM Cabot Microelectronics Corporation (Nasdaq: CCMP), the world�s leading supplier of chemical mechanical planarization (CMP) slurries to the semiconductor industry, announced today that it is scheduled to present at the Sidoti & Company Seventh Annual West Coast Institutional Investor Forum in San Francisco, California, at 11:05 a.m. Central Time, Monday, September 8, 2008. Forward looking and other material information may be discussed during the presentation. About Cabot Microelectronics Cabot Microelectronics Corporation (Nasdaq: CCMP), headquartered in Aurora, Illinois, is the world�s leading supplier of CMP slurries used in semiconductor and data storage manufacturing. The company�s products play a critical role in the production of the most advanced semiconductor devices, enabling the manufacture of smaller, faster and more complex devices by its customers. Since becoming an independent public company in 2000, the company has grown to approximately 800 employees on a global basis. The company's vision is to become the world leader in shaping, enabling and enhancing the performance of surfaces, so the company is leveraging its expertise in CMP slurry formulation, materials and polishing techniques developed for the semiconductor industry and applying it to demanding surface modification applications in other industries where shaping, enabling and enhancing the performance of surfaces is critical to success. For more information about Cabot Microelectronics Corporation, visit www.cabotcmp.comor contact Amy Ford, Director of Investor Relations at (630) 499-2600.