CABOT CORP — Director's Dealing 2006

Jun 16, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2006-06-13

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
2006-06-13	Common Stock	P	100	$31.67	Acquired	7648700	Direct
2006-06-13	Common Stock	P	2100	$31.6757	Acquired	7650800	Direct
2006-06-13	Common Stock	P	3500	$31.68	Acquired	7654300	Direct
2006-06-13	Common Stock	P	40600	$31.69	Acquired	7694900	Direct
2006-06-13	Common Stock	P	107500	$31.70	Acquired	7802400	Direct
2006-06-14	Common Stock	P	100	$31.69	Acquired	7802500	Direct
2006-06-14	Common Stock	P	71000	$31.70	Acquired	7873500	Direct
2006-06-14	Common Stock	P	1900	$31.85	Acquired	7875400	Direct
2006-06-14	Common Stock	P	100	$31.86	Acquired	7875500	Direct
2006-06-14	Common Stock	P	200	$31.87	Acquired	7875700	Direct
2006-06-14	Common Stock	P	500	$31.88	Acquired	7876200	Direct
2006-06-14	Common Stock	P	900	$31.89	Acquired	7877100	Direct
2006-06-14	Common Stock	P	67700	$31.90	Acquired	7944800	Direct
2006-06-14	Common Stock	P	9800	$31.90	Acquired	7954600	Direct
2006-06-15	Common Stock	P	343000	$32.50	Acquired	8297600	Direct

Footnotes

F1: As a result of the purchases causing this filing, 8,297,600 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.

F2: 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 trustee for the Oberndorf Trust, the sole general partner of Oberndorf Family Partners, a family 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.

F3: Additionally, 5,000 shares of the issuer's common stock are owned directly by Betty Jane Weimer.