CABOT CORP — Director's Dealing 2008

Oct 9, 2008

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CABOT CORP (CBT)
CIK: 0000016040
Period of Report: 2008-10-06

Reporting Person: SAN FRANCISCO PARTNERS II LP (10% Owner)
Reporting Person: MCDERMOTT EDWARD H (10% Owner)
Reporting Person: SF ADVISORY PARTNERS LP (10% Owner)
Reporting Person: SPO ADVISORY CORP (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
2008-10-06	Common Stock	S	110900	$28.79	Disposed	304700	Indirect
2008-10-06	Common Stock	S	6800	$29.57	Disposed	297900	Indirect
2008-10-07	Common Stock	S	100000	$28.68	Disposed	197900	Indirect
2008-10-07	Common Stock	S	108400	$29.41	Disposed	89500	Indirect

Footnotes

F1: The entity disposing of these shares is San Francisco Partners II, L.P. ("SF Partners") which sold 326,100 shares.

F2: As a result of the sales causing this filing, 9,662,600 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 partners 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"), William J. Patterson ("WJP") and Edward H. McDermott ("EHM"), the four controlling persons of SPO Corp. Additionally, 89,500 shares of the issuer's common stock are owned directly by SF Partners and may be deemed to be indirectly beneficially owned by (i) SF Advisory Partners, L.P. ("SF Advisory"), the sole general partners of SF Partners, (ii) SPO Corp., the sole general partner of SF Advisory, and (iii) JHS, WEO, WJP and EHM, the four controlling persons of SPO Corp.

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, and (iii) WEO owns 109,000 shares of the issuer's common stock in his IRA, which is self-directed.