European Commission Closes Carbon Black Investigation

June 1, 2005

BOSTON, June 1 /PRNewswire-FirstCall/ -- Cabot Corporation (NYSE: CBT) announced today that it has received notification from the European Commission that the Commission's investigation into possible price-fixing within the European carbon black industry has been closed. European authorities initiated their investigation in November 2002.

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

Contact: Susannah Robinson
Director, Investor Relations
617-342-6129

SOURCE Cabot Corporation