CABOT CORP — Director's Dealing 2005

May 25, 2005

SEC Form 4/A — Form 4/A

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2005-05-23

Reporting Person: Blevi Dirk (Director, Executive Vice President)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2005-05-23	Employee Stock Option (right to buy)	$28.52	A	40000	Acquired	2010-05-12	Common Stock (40000)	Direct

Footnotes

F1: Option grant.