Item 8.01 Other Events.

On February 27, 2009, Cabot Microelectronics Corporation (the "Company") issued a press release entitled "Cabot Microelectronics Corporation Completes Acquisition of Epoch Material Co., Ltd.", a copy of which is attached hereto as Exhibit 99.1 and incorporated herein by reference. The Company has completed the acquisition of Epoch Material Co., Ltd. ("Epoch") from Eternal Chemical Co., Ltd. ("Eternal") for approximately $66 million, which it had previously announced in December 2008. Epoch specializes in the development, manufacture and sale of copper chemical mechanical planarization ("CMP") slurries and CMP cleaning solutions to the semiconductor industry, as well as color filter slurries to the liquid crystal display industry. The Company has initially obtained 90 percent of Epoch's stock, with the remaining 10 percent of the shares scheduled to be transferred to the Company from Eternal in eighteen months.

Item 9.01 Financial Statements and Exhibits.

(c) Exhibits

99.1 Press release, dated February 27, 2009, entitled "Cabot Microelectronics Corporation Completes Acquisition of Epoch Material Co., Ltd."

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