CABOT CORP — Director's Dealing 2005

Oct 26, 2005

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2005-10-21

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2005-10-21	Common Stock	P	100	$31.49	Acquired	6520600	Direct
2005-10-21	Common Stock	P	100	$31.52	Acquired	6520700	Direct
2005-10-21	Common Stock	P	200	$31.53	Acquired	6520900	Direct
2005-10-21	Common Stock	P	1600	$31.54	Acquired	6522500	Direct
2005-10-21	Common Stock	P	1600	$31.55	Acquired	6524100	Direct
2005-10-21	Common Stock	P	600	$31.56	Acquired	6524700	Direct
2005-10-21	Common Stock	P	800	$31.57	Acquired	6525500	Direct
2005-10-21	Common Stock	P	1400	$31.58	Acquired	6526900	Direct
2005-10-21	Common Stock	P	3200	$31.59	Acquired	6530100	Direct
2005-10-21	Common Stock	P	2200	$31.60	Acquired	6532300	Direct
2005-10-21	Common Stock	P	1800	$31.61	Acquired	6534100	Direct
2005-10-21	Common Stock	P	1500	$31.62	Acquired	6535600	Direct
2005-10-21	Common Stock	P	1300	$31.63	Acquired	6536900	Direct
2005-10-21	Common Stock	P	1200	$31.64	Acquired	6538100	Direct
2005-10-21	Common Stock	P	1400	$31.65	Acquired	6539500	Direct
2005-10-21	Common Stock	P	1700	$31.66	Acquired	6541200	Direct
2005-10-21	Common Stock	P	900	$31.67	Acquired	6542100	Direct
2005-10-21	Common Stock	P	3400	$31.68	Acquired	6545500	Direct
2005-10-21	Common Stock	P	1200	$31.69	Acquired	6546700	Direct
2005-10-21	Common Stock	P	2100	$31.70	Acquired	6548800	Direct
2005-10-21	Common Stock	P	1400	$31.71	Acquired	6550200	Direct
2005-10-21	Common Stock	P	2100	$31.72	Acquired	6552300	Direct
2005-10-21	Common Stock	P	3200	$31.73	Acquired	6555500	Direct
2005-10-21	Common Stock	P	1600	$31.74	Acquired	6557100	Direct
2005-10-21	Common Stock	P	2100	$31.75	Acquired	6559200	Direct
2005-10-21	Common Stock	P	800	$31.76	Acquired	6560000	Direct
2005-10-21	Common Stock	P	1300	$31.77	Acquired	6561300	Direct
2005-10-21	Common Stock	P	100	$31.78	Acquired	6561400	Direct
2005-10-21	Common Stock	P	1100	$31.79	Acquired	6562500	Direct
2005-10-21	Common Stock	P	100	$31.80	Acquired	6562600	Direct

Footnotes

F1: 6,253,200 shares of the issuer's common stock are owned directly by SPO Partners II, L.P. ("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. 309,400 shares of the issuer's common stock are owned directly by San Francisco Partners, 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.