CABOT CORP — Director's Dealing 2008

Jan 3, 2008

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2007-12-28

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: Elizabeth R. & William J. Patterson Foundation (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
2007-12-28	Common Stock	P	400	$33.43	Acquired	9584542	Indirect
2007-12-28	Common Stock	P	200	$33.44	Acquired	9584742	Indirect
2007-12-28	Common Stock	P	1000	$33.45	Acquired	9585742	Indirect
2007-12-28	Common Stock	P	400	$33.46	Acquired	9586142	Indirect
2007-12-28	Common Stock	P	500	$33.48	Acquired	9586642	Indirect
2007-12-28	Common Stock	P	400	$33.49	Acquired	9587042	Indirect
2007-12-28	Common Stock	P	600	$33.50	Acquired	9587642	Indirect
2007-12-28	Common Stock	P	100	$33.58	Acquired	9587742	Indirect
2007-12-28	Common Stock	P	700	$33.59	Acquired	9588442	Indirect
2007-12-28	Common Stock	P	900	$33.60	Acquired	9589342	Indirect
2007-12-28	Common Stock	P	300	$33.61	Acquired	9589642	Indirect
2007-12-28	Common Stock	P	400	$33.62	Acquired	9590042	Indirect
2007-12-28	Common Stock	P	500	$33.63	Acquired	9590542	Indirect
2007-12-28	Common Stock	P	500	$33.64	Acquired	9591042	Indirect
2007-12-28	Common Stock	P	700	$33.65	Acquired	9591742	Indirect
2007-12-28	Common Stock	P	100	$33.66	Acquired	9591842	Indirect
2007-12-28	Common Stock	P	100	$33.69	Acquired	9591942	Indirect
2007-12-28	Common Stock	P	200	$33.70	Acquired	9592142	Indirect
2007-12-28	Common Stock	P	700	$33.71	Acquired	9592842	Indirect
2007-12-28	Common Stock	P	1100	$33.72	Acquired	9593942	Indirect
2007-12-28	Common Stock	P	700	$33.73	Acquired	9594642	Indirect
2007-12-28	Common Stock	P	1300	$33.74	Acquired	9595942	Indirect
2007-12-28	Common Stock	P	2400	$33.75	Acquired	9598342	Indirect
2007-12-28	Common Stock	P	300	$33.77	Acquired	9598642	Indirect
2007-12-28	Common Stock	P	100	$33.78	Acquired	9598742	Indirect
2007-12-28	Common Stock	P	100	$33.80	Acquired	9598842	Indirect
2007-12-28	Common Stock	P	200	$33.81	Acquired	9599042	Indirect
2007-12-28	Common Stock	P	200	$33.82	Acquired	9599242	Indirect
2007-12-28	Common Stock	P	300	$33.83	Acquired	9599542	Indirect
2007-12-28	Common Stock	P	300	$33.84	Acquired	9599842	Indirect

Footnotes

F1: The entities directly acquiring the shares reported on this form are SPO Partners II, L.P. ("SPO Partners"), which bought 266,600 shares, and the Elizabeth R. & William J. Patterson Foundation ("WJPFND"), which bought 5,300 shares.

F2: Due to the purchases causing this filing and related filings today, 9,413,100 shares 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 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. These shares are represented in the running total in Column 5 above, which does not include 15,200 shares held by WJPFND.

F3: Additionally, (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, (iii) WEO owns 109,000 shares in his IRA, which is self-directed, and (iv) 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 & William Ernst Oberndorf.