CABOT CORP — Director's Dealing 2006

Nov 14, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2006-11-10

Reporting Person: BRADY WILLIAM J (Executive Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-11-10	Common Stock	M	50000	$28.00	Acquired	203945	Direct
2006-11-10	Common Stock	S	1400	$42.81	Disposed	202545	Direct
2006-11-10	Common Stock	S	5800	$42.82	Disposed	196745	Direct
2006-11-10	Common Stock	S	1200	$42.83	Disposed	195545	Direct
2006-11-10	Common Stock	S	2400	$42.84	Disposed	193145	Direct
2006-11-10	Common Stock	S	1400	$42.85	Disposed	191745	Direct
2006-11-10	Common Stock	S	3700	$42.86	Disposed	188045	Direct
2006-11-10	Common Stock	S	3800	$42.87	Disposed	184245	Direct
2006-11-10	Common Stock	S	9700	$42.88	Disposed	174545	Direct
2006-11-10	Common Stock	S	8300	$42.89	Disposed	166245	Direct
2006-11-10	Common Stock	S	23200	$42.90	Disposed	143045	Direct
2006-11-10	Common Stock	S	1600	$42.91	Disposed	141445	Direct
2006-11-10	Common Stock	S	1000	$42.92	Disposed	140445	Direct
2006-11-10	Common Stock	S	1200	$42.93	Disposed	139245	Direct
2006-11-10	Common Stock	S	300	$42.94	Disposed	138945	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2006-11-10	Employee Stock Option (right to buy)	$28.00	M	50000	Disposed	2008-05-08	Common stock (50000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	5603.3041	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Series B ESOP Convertible Preferred Stock	$		Common stock (10921.616)	74.6123	Indirect

Footnotes

F1: Each share is convertible into 146.3782 shares of the Corporation's common stock.

F2: 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.