Edgar Filing: CABOT CORP

Ownership Submission

FORM 4

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person ^*

SPO ADVISORY CORP

2. Issuer Name and Ticker or Trading Symbol
CABOT CORP [CBT]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

_____ Director	__X__ 10% Owner
_____ Officer (give title below)	_____ Other (specify below)

(Last)

(First)

(Middle)

591 REDWOOD HIGHWAY, SUITE 3215

3. Date of Earliest Transaction (Month/Day/Year)
02/10/2006

(Street)

MILL VALLEY, CA 94941

4. If Amendment, Date Original Filed(Month/Day/Year)

6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person

(City)

(State)

(Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1.Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	02/10/2006		P		6,500	A	$ 36.78	400,950	I ⁽¹⁾ ⁽²⁾	See footnotes
Common Stock	02/10/2006		P		32,700	A	$ 36.8	433,650	I ⁽¹⁾ ⁽²⁾	See footnotes

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security
(Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code
(Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date
(Month/Day/Year)

7. Title and Amount of Underlying Securities
(Instr. 3 and 4)

8. Price of Derivative Security
(Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)

11. Nature of Indirect Beneficial Ownership
(Instr. 4)

Code

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
SPO ADVISORY CORP 591 REDWOOD HIGHWAY, SUITE 3215 MILL VALLEY, CA 94941		X
OBERNDORF WILLIAM E 591 REDWOOD HIGHWAY, SUITE 3215 MILL VALLEY, CA 94941		X
WILLIAM ERNST OBERNDORF TRUST 591 REDWOOD HIGHWAY , SUITE 3215 MILL VALLEY, CA 94941		X
OBERNDORF FAMILY PARTNERS 591 REDWOOD HIGHWAY , SUITE 3215 MILL VALLEY, CA 94941		X

Signatures

Kim M. Silva, Attorney-in-Fact		02/14/2006
^**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	As a result of the purchases causing this filing, (i) 333,650 shares of the issuer's common stock may be deemed to be indirectly beneficially owned by William E. Oberndorf ("WEO"), solely in his capacity as a trustee for the William and Susan Oberndorf Trust, dated 10/15/98 ("Oberndorf Trust"), and (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.
(2)	Additionally, separate from the entities listed above, 7,648,600 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"), 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.
Remarks: The persons listed in Note (2) above ( each a "Reporting Person" ) may be deemed to form a "group", as such term is defined in Rule 13d-5(b)(1) promulgated under the Securities Exchange Act of 1934, for purposes of this filing. This filing shall not be deemed as an admission by any Reporting Person that such person is, for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, the beneficial owner of any equity securities covered by this statement. Each Reporting Person disclaims beneficial ownership of the reported securities except to the extent of such person's pecuniary interest, if any, therein.

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