Cabot Ceases Manufacturing Operations in Australia

October 3, 2005

MELBOURNE, Australia and BOSTON, Oct. 3 /PRNewswire-FirstCall/ -- Cabot Corporation (NYSE: CBT) announced today that its wholly owned subsidiary, Cabot Australasia Pty. Ltd. has ceased manufacturing operations at its Altona carbon black plant as of October 3, 2005. As previously announced a year ago, the decision to close this plant is due to the decline in the domestic carbon black market in Australia. Additionally, Cabot's major domestic feedstock supplier in Australia had announced that it would cease supplying feedstock to Cabot in 2005.

Cabot remains committed to its Australian and New Zealand customers and will continue to provide service directly and through its Australian distributor Multichem and its New Zealand distributor Polychem.

Cabot Corporation is a global specialty chemicals and materials company headquartered in Boston, Massachusetts, USA. Cabot's major products are carbon black, fumed silica, inkjet colorants, capacitor materials, and cesium formate drilling fluids. The website address is: http://www.cabot-corp.com.

Contact:
Ethel Shepard
Corporate Affairs Manager
617-342-6254
ethel_shepard@cabot-corp.com

Susannah Robinson
Director, Investor Relations
617-342-6129
susannah_robinson@cabot-corp.com

SOURCE Cabot Corporation