SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                  SCHEDULE 13D

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 5)*

                                CABOT CORPORATION
                                (Name of Issuer)

                     COMMON STOCK, PAR VALUE $1.00 PER SHARE
                         (Title of Class of Securities)

                                    127055101
                                 (CUSIP Number)

                               SPO Advisory Corp.
                         591 Redwood Highway, Suite 3215
                          Mill Valley, California 94941
                                 (415) 383-6600

                                 with a copy to:

                                Alison S. Ressler
                             Sullivan & Cromwell LLP
                             1888 Century Park East
                       Los Angeles, California 90067-1725
                                 (310) 712-6600

           (Name, Address and Telephone Number of Person Authorized to
                       Receive Notices and Communications)

                                January 10, 2006
             (Date of Event which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D, and is filing this
Schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following
box |_|.

Note. Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7 for other parties
to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

Page 2 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON SPO Partners II, L.P. - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS WC - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 7,648,600 (1) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 7,648,600 (1) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,648,600 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 12.16% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON PN - -------------------------------------------------------------------------------- (1) Power is exercised through its sole general partner, SPO Advisory Partners, L.P.

Page 3 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON SPO Advisory Partners, L.P. - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS Not Applicable - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 7,648,600 (1)(2) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 7,648,600 (1)(2) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,648,600 (1)(2) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 12.16% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON PN - -------------------------------------------------------------------------------- (1) Solely in its capacity as the sole general partner of SPO Partners II, L.P. (2) Power is exercised through its sole general partner, SPO Advisory Corp.

Page 4 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON San Francisco Partners II, L.P. - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS WC - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION California - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 309,400 (1) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 309,400 (1) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 309,400 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.49% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON PN - -------------------------------------------------------------------------------- (1) Power is exercised through its sole general partner, SF Advisory Partners, L.P.

Page 5 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON SF Advisory Partners, L.P. - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS Not Applicable - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 309,400 (1)(2) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 309,400 (1)(2) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 309,400 (1)(2) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.49% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON PN - -------------------------------------------------------------------------------- (1) Solely in its capacity as the sole general partner of San Francisco Partners II, L.P. (2) Power is exercised through its sole general partner, SPO Advisory Corp.

Page 6 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON SPO Advisory Corp. - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS Not Applicable - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 7,958,000 (1)(2) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 7,958,000 (1)(2) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,958,000 (1)(2) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 12.66% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON CO - -------------------------------------------------------------------------------- (1) Solely in its capacity as the sole general partner of SPO Advisory Partners, L.P. with respect to 7,648,600 of such shares; and solely in its capacity as the sole general partner of SF Advisory Partners, L.P. with respect to 309,400 of such shares. (2) Power is exercised through its three controlling persons, John H. Scully, William E. Oberndorf and William J. Patterson.

Page 7 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON John H. Scully - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS Not Applicable - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION USA - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER -0- ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By 7,958,000 (1) Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER -0- ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER 7,958,000 (1) - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,958,000 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 12.66% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON IN - -------------------------------------------------------------------------------- (1) These shares may be deemed to be beneficially owned by Mr. Scully solely in his capacity as one of three controlling persons of SPO Advisory Corp.

Page 8 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON William E. Oberndorf - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS Not Applicable - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION USA - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER -0- ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By 8,352,450 (1) Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER -0- ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER 8,352,450 (1) - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,352,450 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13.28% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON IN - -------------------------------------------------------------------------------- (1) Of these shares, 7,958,000 shares may be deemed to be beneficially owned by Mr. Oberndorf solely in his capacity as one of the three controlling persons of SPO Advisory Corp., 327,150 shares may be deemed to be beneficially owned by Mr. Oberndorf solely in his capacity as a trustee of the William and Susan Oberndorf Trust, dated 10/19/98 and 67,300 shares may be deemed to be beneficially owned by Mr. Oberndorf solely in his capacity as sole general partner of Oberndorf Family Partners, a California limited partnership.

Page 9 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON William and Susan Oberndorf Trust, dated 10/19/98 - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS PF - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION California - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 327,150 (1) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 327,150 (1) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 327,150 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.52% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON OO - -------------------------------------------------------------------------------- (1) Power is exercised through its trustees, William E. Oberndorf and Susan C. Oberndorf.

Page 10 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON Oberndorf Family Partners - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS WC - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION California - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 67,300 (1) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 67,300 (1) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 67,300 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.11% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON PN - -------------------------------------------------------------------------------- (1) Power is exercised through its sole general partner, William E. Oberndorf.

Page 11 of 24 pages CUSIP No. 127055101 - -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSON William J. Patterson - -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3. SEC Use Only - -------------------------------------------------------------------------------- 4. SOURCE OF FUNDS Not Applicable - -------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION USA - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER -0- ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By 7,958,000 (1) Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER -0- ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER 7,958,000 (1) - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,958,000 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 12.66% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON IN - -------------------------------------------------------------------------------- (1) These shares may be deemed to be beneficially owned by Mr. Patterson solely in his capacity as one of three controlling persons of SPO Advisory Corp.

Page 12 of 24 pages This Amendment No. 5 amends the Schedule 13D (the "Original 13D") filed with the Securities and Exchange Commission ("SEC") on August 29, 2005 and as amended on September 14, 2005, September 26, 2005, October 20, 2005 and November 8, 2005. Unless otherwise stated herein, the Original 13D, as previously amended, remains in full force and effect. Terms used herein and not defined herein shall have the meanings ascribed thereto in the Original 13D. ITEM 2. IDENTITY AND BACKGROUND Item 2(a) is hereby amended and restated in its entirety as follows: "The undersigned hereby file this Schedule 13D Statement on behalf of SPO Partners II, L.P., a Delaware limited partnership ("SPO"), SPO Advisory Partners, L.P., a Delaware limited partnership ("SPO Advisory Partners"), San Francisco Partners II, L.P., a California limited partnership ("SFP"), SF Advisory Partners, L.P., a Delaware limited partnership ("SF Advisory Partners"), SPO Advisory Corp., a Delaware corporation ("SPO Advisory Corp."), John H. Scully ("JHS"), William E. Oberndorf ("WEO"), William J. Patterson ("WJP"), the William and Susan Oberndorf Trust, dated 10/19/98 ("Oberndorf Trust"), and Oberndorf Family Partners, a California limited partnership ("OFP"). SPO, SPO Advisory Partners, SFP, SF Advisory Partners, SPO Advisory Corp., JHS, WEO, WJP, the Oberndorf Trust and OFP are sometimes hereinafter referred to as the "Reporting Persons." The Reporting Persons are making this single, joint filing because they may be deemed to constitute a "group" within the meaning of Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act"), although neither the fact of this filing nor anything contained herein shall be deemed to be an admission by the Reporting Persons that a group exists." The subsection titled "WEO" of Item 2(b)-(c) is hereby amended and restated in its entirety as follows: "WEO's business address is 591 Redwood Highway, Suite 3215, Mill Valley, California 94941. His present principal occupation is serving as a managing director of SPO Partners & Co. WEO is one of three controlling persons of SPO Advisory Corp., the sole general partner of SPO Advisory Partners and SF Advisory Partners. WEO is also a trustee for the Oberndorf Trust and the sole general partner of OFP." The following subsections are hereby added to Item 2(b)-(c) in appropriate alphabetical order as follows: "OBERNDORF TRUST "Oberndorf Trust is a living trust, established for the benefit of WEO and his wife, Susan C. Oberndorf. WEO and Ms. Oberndorf are the trustees of Oberndorf Trust. The principal business address of Oberndorf Trust, which also serves as its principal office, is 591 Redwood Highway, Suite 3215, Mill Valley, California 94941. Pursuant to Instruction C to Schedule 13D of the Act, certain information with respect to WEO is set forth above. Ms. Oberndorf's business address is 591 Redwood Highway, Suite 3215, Mill Valley, California 94941. Ms. Oberndorf's present principal occupation is homemaker. "OFP "OFP is a California limited partnership, the principal business of which is the purchase, sale, exchange, acquisition and holding of investment securities. The principal business address of OFP, which also serves as its principal office, is 591 Redwood Highway, Suite 3215, Mill Valley, California 94941. Pursuant to Instruction C to Schedule 13D of the Act, certain information with respect to WEO, the sole general partner of OFP, is set forth above."

Page 13 of 24 pages ITEM 3. SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION. Item 3 is hereby amended and restated in its entirety as follows: The source and amount of the funds used or to be used by the Reporting Persons to purchase Shares are as follows: NAME SOURCE OF FUNDS AMOUNT OF FUNDS - --------------------- --------------------------- --------------- SPO Contributions from Partners $246,120,865 SPO Advisory Partners Not Applicable Not Applicable SFP Contributions from Partners $10,038,218 SF Advisory Partners Not Applicable Not Applicable SPO Advisory Corp. Not Applicable Not Applicable JHS Not Applicable Not Applicable WEO Personal Funds (1) $14,430,442 WJP Not Applicable Not Applicable Oberndorf Trust Personal Funds(1) $11,998,354 OFP Contribution from Partners $ 2,432,088 - ---------- (1) As used herein, the term "Personal Funds" includes sums borrowed from banks and brokerage firm margin accounts, none of which were borrowed or otherwise obtained for the specified purpose of acquiring, holding, trading or voting Shares. ITEM 5. INTEREST IN SECURITIES OF THE ISSUER. Item 5 is hereby amended and restated in its entirety as follows: (a) Percentage interest calculations for each Reporting Person are based upon the Issuer having 62,883,088 total outstanding shares of Common Stock as reported on the Issuer's 10-K filed with the Securities and Exchange Commission on December 14, 2005. SPO The aggregate number of Shares that SPO owns beneficially, pursuant to Rule 13d-3 of the Act, is 7,648,600 Shares, which constitutes approximately 12.16% of the outstanding Shares. SPO Advisory Partners Because of its position as the sole general partner of SPO, SPO Advisory Partners may, pursuant to Rule 13d-3 of the Act, be deemed to be the beneficial owner of 7,648,600 Shares, which constitutes approximately 12.16% of the outstanding Shares.

Page 14 of 24 pages SFP The aggregate number of Shares that SFP owns beneficially, pursuant to Rule 13d-3 of the Act, is 309,400 Shares, which constitutes approximately 0.49% of the outstanding Shares. SF Advisory Partners Because of its position as the sole general partner of SFP, SF Advisory Partners may, pursuant to Rule 13d-3 of the Act, be deemed to be the beneficial owner of 309,400 Shares, which constitutes approximately 0.49% of the outstanding Shares. SPO Advisory Corp. Because of its positions as the sole general partner of each of SPO Advisory Partners and SF Advisory Partners, SPO Advisory Corp. may, pursuant to Rule 13d-3 of the Act, be deemed to be the beneficial owner of 7,958,000 Shares in the aggregate, which constitutes approximately 12.66% of the outstanding Shares. JHS Because of his position as a control person of SPO Advisory Corp., JHS may, pursuant to Rule 13d-3 of the Act, be deemed to be the beneficial owner of 7,958,000 Shares, which constitutes approximately 12.66% of the outstanding Shares. WEO Individually, and because of his positions as a control person of SPO Advisory Corp., a trustee of the Oberndorf Trust and sole general partner of OFP, WEO may, pursuant to Rule 13d-3 of the Act, be deemed to be the beneficial owner of 8,352,450 Shares in the aggregate, which constitutes approximately 13.28% of the outstanding Shares. WJP Because of his position as a control person of SPO Advisory Corp., WJP may, pursuant to Rule 13d-3 of the Act, be deemed to be the beneficial owner of 7,958,000 Shares, which constitutes approximately 12.66% of the outstanding Shares. Oberndorf Trust The aggregate number of Shares that the Oberndorf Trust owns beneficially, pursuant to Rule 13d-3 of the Act, is 327,150 Shares, which constitutes approximately 0.52% of the outstanding Shares. OFP The aggregate number of Shares that OFP owns beneficially, pursuant to Rule 13d-3 of the Act, is 67,300 Shares, which constitutes approximately 0.11% of the outstanding Shares. To the best of the knowledge of each of the Reporting Persons, other than as set forth above, none of the persons named in Item 2 hereof is the beneficial owner of any Shares.

Page 15 of 24 pages (b) SPO Acting through its sole general partner, SPO has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 7,648,600 Shares. SPO Advisory Partners Acting through its sole general partner and in its capacity as the sole general partner of SPO, SPO Advisory Partners has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 7,648,600 Shares. SFP Acting through its sole general partner, SFP has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 309,400 Shares. SF Advisory Partners Acting through its sole general partner and in its capacity as the sole general partner of SFP, SF Advisory Partners has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 309,400 Shares. SPO Advisory Corp. Acting through its controlling persons and in its capacities as the sole general partner of each of SPO Advisory Partners and SF Advisory Partners, SPO Advisory Corp. has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 7,958,000 Shares in the aggregate. JHS As one of three controlling persons of SPO Advisory Corp., which is the sole general partner of each of SPO Advisory Partners and SF Advisory Partners, JHS may be deemed to have shared power with WEO and WJP to vote or to direct the vote and to dispose or to direct the disposition of 7,958,000 Shares held by SPO and SFP in the aggregate. WEO As one of three controlling persons of SPO Advisory Corp., which is the sole general partner of each of SPO Advisory Partners and SF Advisory Partners, WEO may be deemed to have shared power with JHS and WJP to vote or to direct the vote and to dispose or to direct the disposition of 7,958,000 Shares held by SPO and SFP in the aggregate. WEO may be deemed to have shared power to vote or to direct the vote and to dispose or to direct the disposition of 327,150 Shares held in the Oberndorf Trust. Individually, and because of his position as the sole general partner of OFP, WEO has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 67,300 Shares held by OFP. WJP As one of three controlling persons of SPO Advisory Corp., which is the sole general partner of each of SPO Advisory Partners and SF Advisory Partners, WJP may be deemed to have shared power with JHS and WEO to vote or to direct the vote and to dispose or to direct the disposition of 7,958,000 Shares held by SPO and SFP in the aggregate.

Page 16 of 24 pages Oberndorf Trust Acting through its trustees, Oberndorf Trust has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 327,150 Shares in the aggregate. OFP OFP has the sole power to vote or to direct the vote and to dispose or to direct the disposition of 67,300 Shares. (c) During the past 60 days, the Reporting Persons purchased Shares in open market transactions as set forth on Schedule I attached hereto. Except as set forth in this paragraph (c), to the best of the knowledge of each of the Reporting Persons, none of the persons named in response to paragraph (a) has effected any transactions in Shares during the past 60 days. (d) Each of the Reporting Persons affirms that no person other than such Reporting Person has the right to receive or the power to direct the receipt of distributions with respect to, or the proceeds from the sale of, Shares owned by such Reporting Person. (e) Not applicable. ITEM 7. MATERIAL TO BE FILED AS EXHIBITS. Item 7 is hereby amended and restated in its entirety as follows: Exhibit A: Agreement pursuant to Rule 13d-1(k) Exhibit B: Power of Attorney

Page 17 of 24 pages SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Dated January 12, 2006 By: /s/ Kim M. Silva -------------------------------- Kim M. Silva Attorney-in-Fact for: SPO PARTNERS II, L.P.(1) SPO ADVISORY PARTNERS, L.P.(1) SAN FRANCISCO PARTNERS II, L.P.(1) SF ADVISORY PARTNERS, L.P.(1) SPO ADVISORY CORP.(1) JOHN H. SCULLY(1) WILLIAM E. OBERNDORF(1) WILLIAM J. PATTERSON(1) WILLIAM AND SUSAN OBERNDORF TRUST, DATED 10/19/98 (2) OBERNDORF FAMILY PARTNERS (2) (1) A Power of Attorney authorizing Kim M. Silva to act on behalf of this person or entity has been previously filed with the Securities and Exchange Commission. (2) A Power of Attorney authorizing Kim M. Silva to act on behalf of this person or entity is filed as Exhibit B.

Page 18 of 24 pages SCHEDULE I TO SCHEDULE 13D DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - --------------------- ----------- ---- ---------------- --------- --------------------- SPO Partners II, L.P. 11/11/05 Buy 10,000 31.64 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 100 31.69 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 100 31.70 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 400 31.75 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 200 31.80 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 200 31.83 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 500 31.85 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 400 31.86 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 300 31.87 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 200 31.88 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 500 31.90 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 2,600 31.91 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 300 31.92 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 3,300 31.93 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 2,500 31.94 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 1,800 31.95 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 4,400 31.96 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 1,400 31.97 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 3,500 31.98 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 3,300 31.99 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 1,500 32.00 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 100 32.01 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 1,200 32.02 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 1,000 32.03 Open Market/Broker

Page 19 of 24 pages SCHEDULE I TO SCHEDULE 13D DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - --------------------- ----------- ---- ---------------- --------- --------------------- SPO Partners II, L.P. 11/11/05 Buy 200 32.04 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 1,000 32.05 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 3,500 32.06 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 5,600 32.07 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 3,900 32.08 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 900 32.09 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 9,400 32.10 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 600 32.26 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 300 32.27 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 400 32.28 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 100 32.29 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 10,900 32.30 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 900 32.31 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 600 32.32 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 600 32.33 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 600 32.34 Open Market/Broker SPO Partners II, L.P. 11/11/05 Buy 700 32.35 Open Market/Broker SPO Partners II, L.P. 11/18/05 Buy 4,200 33.90 Open Market/Broker SPO Partners II, L.P. 11/18/05 Buy 100,000 34.00 Privately Negotiated Transaction William and Susan Oberndorf 12/20/05 Buy 600 35.32 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 100 35.34 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 1,000 35.35 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 1,400 35.36 Open Market/Broker Trust, dated 10/19/98

Page 20 of 24 pages SCHEDULE I TO SCHEDULE 13D DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - --------------------- ----------- ---- ---------------- --------- --------------------- William and Susan Oberndorf 12/20/05 Buy 3,000 35.37 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 200 35.38 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 500 35.39 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 3,900 35.40 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 14,400 35.41 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 300 35.42 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 6,100 35.45 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 3,600 35.46 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 1,500 35.47 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 4,600 35.48 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 8,300 35.49 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/20/05 Buy 50,500 35.50 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/21/05 Buy 200 35.47 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/21/05 Buy 50 35.48 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/21/05 Buy 150 35.49 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 12/21/05 Buy 42,650 35.50 Open Market/Broker Trust, dated 10/19/98

Page 21 of 24 pages SCHEDULE I TO SCHEDULE 13D DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - --------------------- ----------- ---- ---------------- --------- --------------------- Oberndorf Family Partners 12/21/05 Buy 200 35.47 Open Market/Broker Oberndorf Family Partners 12/21/05 Buy 50 35.48 Open Market/Broker Oberndorf Family Partners 12/21/05 Buy 150 35.49 Open Market/Broker Oberndorf Family Partners 12/21/05 Buy 42,650 35.50 Open Market/Broker William and Susan Oberndorf 1/6/06 Buy 420 37.68 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 420 37.69 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 8,579 37.70 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 3,300 37.71 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 1,079 37.72 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 2,520 37.73 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 1,559 37.74 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 32,573 37.75 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 280 37.68 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 280 37.69 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 5,721 37.70 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 2,200 37.71 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 721 37.72 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 1,680 37.73 Open Market/Broker Trust, dated 10/19/98

Page 22 of 24 pages SCHEDULE I TO SCHEDULE 13D DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - --------------------- ----------- ---- ---------------- --------- --------------------- William and Susan Oberndorf 1/6/06 Buy 1,041 37.74 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/6/06 Buy 21,727 37.75 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 400 37.43 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 400 37.44 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 500 37.45 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 800 37.46 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 1,900 37.47 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 500 37.48 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 600 37.49 Open Market/Broker Trust, dated 10/19/98 William and Susan Oberndorf 1/9/06 Buy 94,900 37.50 Open Market/Broker Trust, dated 10/19/98 Oberndorf Family Partners 1/9/06 Buy 600 37.35 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 18,450 37.20 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 300 37.44 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 500 37.46 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 400 37.47 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 600 37.48 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 800 37.49 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 800 37.50 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 100 37.53 Open Market/Broker

Page 23 of 24 pages SCHEDULE I TO SCHEDULE 13D DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - --------------------- ----------- ---- ---------------- --------- --------------------- Oberndorf Family Partners 1/10/06 Buy 300 37.55 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 300 37.57 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 700 37.59 Open Market/Broker Oberndorf Family Partners 1/10/06 Buy 400 37.60 Open Market/Broker

Page 24 of 24 pages EXHIBIT INDEX EXHIBIT DOCUMENT DESCRIPTION PAGE NO. - ------- ------------------------------------ -------- A Agreement Pursuant to Rule 13d-1(k) 1 B Power of Attorney 2

                                    EXHIBIT A

         Pursuant to Rule 13d-1(k) of Regulation 13D-G of the General Rules and
Regulations of the Securities and Exchange Commission under the Securities
Exchange Act of 1934, as amended, the undersigned agrees that the statement to
which this Exhibit is attached is filed on behalf of each of them in the
capacities set forth below.


Dated January 12, 2006                   By:       /s/ Kim M. Silva
                                               --------------------------------
                                                   Kim M. Silva

                                           Attorney-in-Fact for:

                                           SPO PARTNERS II, L.P.(1)
                                           SPO ADVISORY PARTNERS, L.P.(1)
                                           SAN FRANCISCO PARTNERS II, L.P.(1)
                                           SF ADVISORY PARTNERS, L.P.(1)
                                           SPO ADVISORY CORP.(1)
                                           JOHN H. SCULLY(1)
                                           WILLIAM E. OBERNDORF(1)
                                           WILLIAM J. PATTERSON(1)
                                           WILLIAM AND SUSAN OBERNDORF TRUST,
                                           DATED 10/19/98 (2)
                                           OBERNDORF FAMILY PARTNERS (2)

                                           (1) A Power of Attorney
                                           authorizing Kim M. Silva to
                                           act on behalf of this
                                           person or entity has been previously
                                           filed with the Securities and
                                           Exchange Commission.

                                           (2) A Power of Attorney authorizing
                                           Kim M. Silva to act on behalf of
                                           this person or entity is filed as
                                           Exhibit B.

                                    EXHIBIT B

                                POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that William and Susan Oberndorf Trust,
dated 10/19/98 and Oberndorf Family Partners (each a "Grantor") have made,
constituted and appointed, and by these presents do make, constitute and
appoint, each of William E. Oberndorf and Kim M. Silva (each an "Attorney"), the
true and lawful agent and attorney-in-fact, with full power of substitution and
resubstitution, of the Grantor, for and in Grantor's name, place and stead, in
any and all capacities, to do all or any of the following acts, matters and
things:

     1.   To sign on behalf of the Grantor statements on Schedule 13D or 13G or
          Forms 3, 4 and 5, or amendments thereto pursuant to Section 13(d) or
          Section 16 under the Securities Exchange Act of 1934.

     2.   To do all such other acts and things as, in such Attorney's
          discretion, he or she deems appropriate or desirable for the purpose
          of filing such statements on Schedule 13D or 13G or Forms 3, 4 and 5,
          or amendments thereto.

     3.   To appoint in writing one or more substitutes who shall have the power
          to act on behalf of the Grantor as if that substitute or those
          substitutes shall have been originally appointed Attorney (s) by this
          Power of Attorney and/or to revoke any such appointment at any time
          without assigning any reason therefor.

The Grantor hereby ratifies and confirms all that said agents and
attorneys-in-fact or any substitute or substitutes may lawfully do or cause to
be done by virtue hereof. This Power of Attorney shall remain in full force and
effect until the undersigned is no longer required to file Forms 3, 4 and 5 or
to file reports under Section 13(d) of the Securities Exchange Act of 1934 with
respect to the undersigned's holdings of and transactions in securities issued
by Cabot Corporation, unless earlier revoked by the undersigned in a signed
writing delivered to the foregoing attorneys-in-fact.

The words Grantor and Attorney shall include all grantors and attorneys under
this Power of Attorney.

                      [Signatures on the Following Pages.]

IN WITNESS WHEREOF, each Grantor duly assents to this Power of Attorney by his, her or its signature as of the 12th day of January, 2006. WILLIAM AND SUSAN OBERNDORF TRUST, DATED 10/19/98 By: /s/ William E. Oberndorf ------------------------------ Name: William E. Oberndorf Title: Trustee OBERNDORF FAMILY PARTNERS By: /s/ William E. Oberndorf ------------------------------ Name: William E. Oberndorf Title: General Partner