CABOT CORP — Director's Dealing 2005

Oct 31, 2005

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2005-10-27

Reporting Person: SPO ADVISORY CORP (10% Owner)
Reporting Person: SPO PARTNERS II LP (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2005-10-27	Common Stock	P	600	$32.30	Acquired	6767700	Direct
2005-10-27	Common Stock	P	400	$32.31	Acquired	6768100	Direct
2005-10-27	Common Stock	P	500	$32.32	Acquired	6768600	Direct
2005-10-27	Common Stock	P	1300	$32.33	Acquired	6769900	Direct
2005-10-27	Common Stock	P	1100	$32.34	Acquired	6771000	Direct
2005-10-27	Common Stock	P	600	$32.35	Acquired	6771600	Direct
2005-10-27	Common Stock	P	400	$32.36	Acquired	6772000	Direct
2005-10-27	Common Stock	P	600	$32.38	Acquired	6772600	Direct
2005-10-27	Common Stock	P	1100	$32.39	Acquired	6773700	Direct
2005-10-27	Common Stock	P	600	$32.40	Acquired	6774300	Direct
2005-10-27	Common Stock	P	200	$32.41	Acquired	6774500	Direct
2005-10-27	Common Stock	P	1200	$32.42	Acquired	6775700	Direct
2005-10-27	Common Stock	P	1100	$32.43	Acquired	6776800	Direct
2005-10-27	Common Stock	P	1500	$32.44	Acquired	6778300	Direct
2005-10-27	Common Stock	P	1600	$32.45	Acquired	6779900	Direct
2005-10-27	Common Stock	P	3100	$32.46	Acquired	6783000	Direct
2005-10-27	Common Stock	P	1700	$32.47	Acquired	6784700	Direct
2005-10-27	Common Stock	P	3200	$32.48	Acquired	6787900	Direct
2005-10-27	Common Stock	P	1700	$32.49	Acquired	6789600	Direct
2005-10-27	Common Stock	P	1900	$32.50	Acquired	6791500	Direct
2005-10-27	Common Stock	P	1200	$32.51	Acquired	6792700	Direct
2005-10-27	Common Stock	P	1500	$32.52	Acquired	6794200	Direct
2005-10-27	Common Stock	P	1200	$32.53	Acquired	6795400	Direct
2005-10-27	Common Stock	P	1700	$32.54	Acquired	6797100	Direct
2005-10-27	Common Stock	P	2500	$32.55	Acquired	6799600	Direct
2005-10-27	Common Stock	P	700	$32.56	Acquired	6800300	Direct
2005-10-27	Common Stock	P	300	$32.57	Acquired	6800600	Direct
2005-10-27	Common Stock	P	700	$32.58	Acquired	6801300	Direct
2005-10-27	Common Stock	P	300	$32.59	Acquired	6801600	Direct

Footnotes

F1: 6,492,200 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.