CABOT CORP — Director's Dealing 2004

Nov 5, 2004

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2004-11-03

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2004-11-03	Common Stock	M	7400	$10.8336	Acquired	7400	Direct
2004-11-03	Common Stock	S	7400	$35.00	Disposed	0	Direct
2004-11-04	Common Stock	M	4000	$10.8336	Acquired	4000	Direct
2004-11-04	Common Stock	S	3000	$35.00	Disposed	1000	Direct
2004-11-04	Common Stock	S	1000	$35.06	Disposed	0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2004-11-03	Employee Stock Option (right to buy)	$10.8336	M	7400	Disposed	2004-11-11	Common Stock (7400)	Direct
2004-11-04	Employee Stock Option (right to buy)	$10.8336	M	4000	Disposed	2004-11-11	Common Stock (4000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	9784.07	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Series B ESOP Convertible Preferred Stock	$		Common Stock (17514.38)	119.65	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.