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	300	$33.21	Acquired	9562400	Indirect
2007-12-28	Common Stock	P	200	$33.22	Acquired	9562600	Indirect
2007-12-28	Common Stock	P	300	$33.23	Acquired	9562900	Indirect
2007-12-28	Common Stock	P	800	$33.24	Acquired	9563700	Indirect
2007-12-28	Common Stock	P	300	$33.245	Acquired	9564000	Indirect
2007-12-28	Common Stock	P	100	$33.25	Acquired	9564100	Indirect
2007-12-28	Common Stock	P	600	$33.26	Acquired	9564700	Indirect
2007-12-28	Common Stock	P	100	$33.263	Acquired	9564800	Indirect
2007-12-28	Common Stock	P	300	$33.265	Acquired	9565100	Indirect
2007-12-28	Common Stock	P	400	$33.27	Acquired	9565500	Indirect
2007-12-28	Common Stock	P	500	$33.275	Acquired	9566000	Indirect
2007-12-28	Common Stock	P	100	$33.278	Acquired	9566100	Indirect
2007-12-28	Common Stock	P	500	$33.28	Acquired	9566600	Indirect
2007-12-28	Common Stock	P	100	$33.283	Acquired	9566700	Indirect
2007-12-28	Common Stock	P	400	$33.285	Acquired	9567100	Indirect
2007-12-28	Common Stock	P	2042	$33.29	Acquired	9569142	Indirect
2007-12-28	Common Stock	P	1400	$33.295	Acquired	9570542	Indirect
2007-12-28	Common Stock	P	4200	$33.30	Acquired	9574742	Indirect
2007-12-28	Common Stock	P	1700	$33.31	Acquired	9576442	Indirect
2007-12-28	Common Stock	P	1300	$33.32	Acquired	9577742	Indirect
2007-12-28	Common Stock	P	700	$33.33	Acquired	9578442	Indirect
2007-12-28	Common Stock	P	500	$33.34	Acquired	9578942	Indirect
2007-12-28	Common Stock	P	1200	$33.35	Acquired	9580142	Indirect
2007-12-28	Common Stock	P	600	$33.36	Acquired	9580742	Indirect
2007-12-28	Common Stock	P	1000	$33.37	Acquired	9581742	Indirect
2007-12-28	Common Stock	P	700	$33.38	Acquired	9582442	Indirect
2007-12-28	Common Stock	P	200	$33.39	Acquired	9582642	Indirect
2007-12-28	Common Stock	P	600	$33.40	Acquired	9583242	Indirect
2007-12-28	Common Stock	P	200	$33.41	Acquired	9583442	Indirect
2007-12-28	Common Stock	P	700	$33.42	Acquired	9584142	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.