CABOT CORP — Director's Dealing 2006

Jul 19, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2006-07-14

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: SF ADVISORY PARTNERS LP (10% Owner)
Reporting Person: SAN FRANCISCO 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
2006-07-14	Common Stock	P	800	$31.95	Acquired	9111250	Indirect
2006-07-14	Common Stock	P	200	$31.96	Acquired	9111450	Indirect
2006-07-14	Common Stock	P	486	$31.9659	Acquired	9111936	Indirect
2006-07-14	Common Stock	P	900	$31.97	Acquired	9112836	Indirect
2006-07-14	Common Stock	P	300	$31.98	Acquired	9113136	Indirect
2006-07-14	Common Stock	P	314	$32.00	Acquired	9113450	Indirect
2006-07-17	Common Stock	P	1600	$31.90	Acquired	9115050	Indirect
2006-07-17	Common Stock	P	900	$31.91	Acquired	9115950	Indirect
2006-07-17	Common Stock	P	4200	$31.92	Acquired	9120150	Indirect
2006-07-17	Common Stock	P	10400	$31.93	Acquired	9130550	Indirect
2006-07-17	Common Stock	P	4000	$31.94	Acquired	9134550	Indirect
2006-07-17	Common Stock	P	19600	$31.95	Acquired	9154150	Indirect
2006-07-18	Common Stock	P	300	$31.81	Acquired	9154450	Indirect
2006-07-18	Common Stock	P	1000	$31.84	Acquired	9155450	Indirect
2006-07-18	Common Stock	P	500	$31.85	Acquired	9155950	Indirect
2006-07-18	Common Stock	P	1300	$31.87	Acquired	9157250	Indirect
2006-07-18	Common Stock	P	900	$31.88	Acquired	9158150	Indirect
2006-07-18	Common Stock	P	200	$31.89	Acquired	9158350	Indirect
2006-07-18	Common Stock	P	2200	$31.90	Acquired	9160550	Indirect
2006-07-18	Common Stock	P	400	$31.91	Acquired	9160950	Indirect
2006-07-18	Common Stock	P	1200	$31.92	Acquired	9162150	Indirect
2006-07-18	Common Stock	P	1800	$31.93	Acquired	9163950	Indirect
2006-07-18	Common Stock	P	400	$31.94	Acquired	9164350	Indirect
2006-07-18	Common Stock	P	1700	$31.95	Acquired	9166050	Indirect
2006-07-18	Common Stock	P	6200	$31.9527	Acquired	9172250	Indirect

Footnotes

F1: The entities acquiring these shares are SPO Partners II, L.P. ("SPO Partners") and San Francisco Partners, L.P. ("SF Partners"). 62,300 of these shares were acquired by SPO Partners and 106,200 were acquired by SF Partners.

F2: As a result of the purchases causing this filing, 8,414,700 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 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.