CABOT CORP — Director's Dealing 2006

Jul 26, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2006-07-21

Reporting Person: SPO ADVISORY CORP (10% Owner)
Reporting Person: SPO ADVISORY PARTNERS LP (10% Owner)
Reporting Person: SPO PARTNERS II LP (10% Owner)
Reporting Person: SCULLY JOHN H (10% Owner)
Reporting Person: OBERNDORF WILLIAM E (10% Owner)
Reporting Person: PATTERSON WILLIAM J (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-07-21	Common Stock	P	600	$31.80	Acquired	9335150	Indirect
2006-07-21	Common Stock	P	1300	$31.81	Acquired	9336450	Indirect
2006-07-21	Common Stock	P	400	$31.82	Acquired	9336850	Indirect
2006-07-21	Common Stock	P	600	$31.83	Acquired	9337450	Indirect
2006-07-21	Common Stock	P	900	$31.84	Acquired	9338350	Indirect
2006-07-21	Common Stock	P	3600	$31.85	Acquired	9341950	Indirect
2006-07-21	Common Stock	P	5000	$31.86	Acquired	9346950	Indirect
2006-07-21	Common Stock	P	5100	$31.87	Acquired	9352050	Indirect
2006-07-21	Common Stock	P	500	$31.88	Acquired	9352550	Indirect
2006-07-21	Common Stock	P	200	$31.89	Acquired	9352750	Indirect
2006-07-21	Common Stock	P	700	$31.90	Acquired	9353450	Indirect
2006-07-21	Common Stock	P	13900	$31.91	Acquired	9367350	Indirect
2006-07-21	Common Stock	P	100	$31.93	Acquired	9367450	Indirect
2006-07-21	Common Stock	P	700	$31.94	Acquired	9368150	Indirect
2006-07-21	Common Stock	P	300	$31.95	Acquired	9368450	Indirect
2006-07-21	Common Stock	P	300	$31.96	Acquired	9368750	Indirect
2006-07-21	Common Stock	P	400	$31.97	Acquired	9639150	Indirect
2006-07-21	Common Stock	P	800	$31.98	Acquired	9369950	Indirect
2006-07-24	Common Stock	P	200	$31.92	Acquired	9370150	Indirect
2006-07-24	Common Stock	P	300	$31.93	Acquired	9370450	Indirect
2006-07-24	Common Stock	P	800	$31.94	Acquired	9371250	Indirect
2006-07-24	Common Stock	P	1100	$31.95	Acquired	9372350	Indirect
2006-07-24	Common Stock	P	1700	$31.96	Acquired	9374050	Indirect
2006-07-24	Common Stock	P	1600	$31.97	Acquired	9375650	Indirect
2006-07-24	Common Stock	P	800	$31.98	Acquired	9376450	Indirect
2006-07-24	Common Stock	P	1000	$31.99	Acquired	9377450	Indirect
2006-07-24	Common Stock	P	7400	$32.00	Acquired	9384850	Indirect

Footnotes

F1: The entity acquiring these shares is SPO Partners II, L.P. ("SPO Partners"). The entire 105,900 shares were acquired by SPO Partners.

F2: As a result of the purchases causing this filing, 8,520,600 shares of the issuer's common stock are owned directly by SPO Partners, and may be deemed to be indirectly beneficially owned by (i) SPO Advisory Partners, L.P. ("SPO Advisory"), the sole general partner of SPO Partners, (ii) SPO Advisory Corp. ("SPO Corp."), the sole general partner of SPO Advisory, and (iii) John H. Scully ("JHS"), William E. Oberndorf ("WEO") and William J. Patterson ("WJP"), the three controlling persons of SPO Corp. 415,600 shares of the issuer's common stock are owned directly by San Francisco Partners, II, L.P. ( "SF Partners"), and may be deemed to be indirectly beneficially owned by (i) SF Advisory Partners, L.P. ("SF Advisory"), the sole general partner of SF Partners, (ii) SPO Corp., the sole general partner of SF Advisory, and (iii) JHS, WEO and WJP, the three controlling persons of SPO Corp.

F3: Additionally, separate from the entities above, (i) 333,650 shares of the issuer's common stock may be deemed to be indirectly beneficially owned by WEO, solely in his capacity as a trustee for the William and Susan Oberndorf Trust, dated 10/15/98 ("Oberndorf Trust"), (ii) 100,000 shares may be deemed to be indirectly beneficially owned by WEO solely in his capacity as general partner of Oberndorf Family Partners, a California limited partnership and (iii) 10,000 shares may be deemed to be indirectly beneficially owned by WEO solely in his capacity as trustee for the accounts of his two children, Peter C. Oberndorf and William Ernst Oberndorf.

F4: Additionally, 5,000 shares of the issuer's common stock are owned directly by Betty Jane Weimer.