CABOT CORP — Director's Dealing 2004

Nov 3, 2004

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2004-11-01

Reporting Person: BURNES KENNETT F (Director, Chairman, CEO and President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2004-11-01	Common Stock	M	85557	$10.8336	Acquired	85557	Direct
2004-11-01	Common Stock	S	100	$35.14	Disposed	85457	Direct
2004-11-01	Common Stock	S	100	$35.13	Disposed	85357	Direct
2004-11-01	Common Stock	S	1500	$35.12	Disposed	83857	Direct
2004-11-01	Common Stock	S	1900	$35.11	Disposed	81957	Direct
2004-11-01	Common Stock	S	1757	$35.10	Disposed	80200	Direct
2004-11-01	Common Stock	S	1300	$35.09	Disposed	78900	Direct
2004-11-01	Common Stock	S	2000	$35.08	Disposed	76900	Direct
2004-11-01	Common Stock	S	900	$35.07	Disposed	76000	Direct
2004-11-01	Common Stock	S	2200	$35.06	Disposed	73800	Direct
2004-11-01	Common Stock	S	2700	$35.05	Disposed	71100	Direct
2004-11-01	Common Stock	S	10300	$35.04	Disposed	60800	Direct
2004-11-01	Common Stock	S	2200	$35.03	Disposed	58600	Direct
2004-11-01	Common Stock	S	2500	$35.02	Disposed	56100	Direct
2004-11-01	Common Stock	S	3000	$35.01	Disposed	53100	Direct
2004-11-01	Common Stock	S	3500	$35.00	Disposed	49600	Direct
2004-11-01	Common Stock	S	5000	$34.99	Disposed	44600	Direct
2004-11-01	Common Stock	S	4000	$34.98	Disposed	40600	Direct
2004-11-01	Common Stock	S	2500	$34.97	Disposed	38100	Direct
2004-11-01	Common Stock	S	16700	$34.96	Disposed	21400	Direct
2004-11-01	Common Stock	S	6900	$34.95	Disposed	14500	Direct
2004-11-01	Common Stock	S	500	$34.94	Disposed	14000	Direct
2004-11-01	Common Stock	S	5900	$34.93	Disposed	8100	Direct
2004-11-01	Common Stock	S	1300	$34.92	Disposed	6800	Direct
2004-11-01	Common Stock	S	4800	$34.91	Disposed	2000	Direct
2004-11-01	Common Stock	S	2000	$34.87	Disposed	0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2004-11-01	Employee Stock Option (right to buy)	$10.8336	M	85557	Disposed	2004-11-11	Common Stock (85557)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	9778.16	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Series B ESOP Convertible Preferred Stock	$		Common Stock (17752.41)	121.28	Indirect

Footnotes

F1: The options were granted on November 11, 1999 to Mr. Burnes in lieu of his cash bonus and were immediately exercisable.

F2: Each share is convertible into 146.4 shares of the Corporation's common stock.

F3: Under the Retirement Savings Plan, the Corporation allocates Series B ESOP Convertible Preferred Stock to each participant's account on a quarterly basis. Subject to certain terms and conditions of the Retirement Savings Plan, participants may elect to receive distributions of their vested account balance in the form of shares of the Corporation's common stock or cash. Generally, a participant is 20% vested in his account after 2 years of service with the Corporation; 40% vested after 3 years of service; 60% vested after 4 years of service; and 100% vested after 5 years of service.