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

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 1)*

                                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)

                                 SEPTEMBER 12, 2005
             (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 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 4,692,500 (1) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 4,692,500 (1) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,692,500 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.6% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON PN - -------------------------------------------------------------------------------- (1) Power is exercised through its sole general partner, SPO Advisory Partners, L.P.

Page 3 of 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 4,692,500 (1)(2) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 4,692,500 (1)(2) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,692,500 (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) 7.6% - -------------------------------------------------------------------------------- 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 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION California - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 298,500 (1) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 298,500 (1) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 298,500 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.5% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON PN - -------------------------------------------------------------------------------- (1) Power is exercised through its sole general partner, SF Advisory Partners, L.P.

Page 5 of 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 298,500 (1)(2) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 298,500 (1)(2) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 298,500 (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) 0.5% - -------------------------------------------------------------------------------- 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 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER 4,991,000 (1)(2) ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By -0- Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER 4,991,000 (1)(2) ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER -0- - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,991,000 (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) 8.1% - -------------------------------------------------------------------------------- 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 4,692,500 of such shares; and solely in its capacity as the sole general partner of SF Advisory Partners, L.P. with respect to 298,500 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 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION USA - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER -0- ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By 4,991,000 (1) Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER -0- ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER 4,991,000 (1) - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,991,000 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 8.1% - -------------------------------------------------------------------------------- 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 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION USA - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER -0- ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By 4,991,000 (1) Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER -0- ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER 4,991,000 (1) - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,991,000 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 8.1% - -------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON IN - -------------------------------------------------------------------------------- (1) These shares may be deemed to be beneficially owned by Mr. Oberndorf solely in his capacity as one of three controlling persons of SPO Advisory Corp.

Page 9 of 35 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(e) OR 2(f) |_| - -------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION USA - -------------------------------------------------------------------------------- 7. SOLE VOTING POWER -0- ------------------------------------------------------ Number Of Shares 8. SHARED VOTING POWER Beneficially Owned By 4,991,000 (1) Each Reporting Person ------------------------------------------------------ With 9. SOLE DISPOSITIVE POWER -0- ------------------------------------------------------ 10. SHARED DISPOSITIVE POWER 4,991,000 (1) - -------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,991,000 (1) - -------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES |_| - -------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 8.1% - -------------------------------------------------------------------------------- 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 10 of 35 pages This Amendment No. 1 amends the Schedule 13D (the "Original 13D") filed with the Securities and Exchange Commission ("SEC") on August 29, 2005. Unless otherwise stated herein, the Original 13D remains in full force and effect. Terms used herein and not defined herein shall have the meanings ascribed thereto in the Original 13D. 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 $152,328,132 SPO Advisory Partners Not Applicable Not Applicable SFP Contributions from Partners $9,690,217 SF Advisory Partners Not Applicable Not Applicable SPO Advisory Corp. Not Applicable Not Applicable JHS Not Applicable Not Applicable WEO Not Applicable Not Applicable WJP Not Applicable Not Applicable 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 62,030,447 total outstanding shares of Common Stock as reported on the Issuer's 10-Q filed with the Securities and Exchange Commission on August 9, 2005. SPO The aggregate number of Shares that SPO owns beneficially, pursuant to Rule 13d-3 of the Act, is 4,692,500 Shares, which constitutes approximately 7.6% 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 4,692,500 Shares, which constitutes approximately 7.6% of the outstanding Shares.

Page 11 of 35 pages SFP The aggregate number of Shares that SFP owns beneficially, pursuant to Rule 13d-3 of the Act, is 298,500 Shares, which constitutes approximately 0.5% 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 298,500 Shares, which constitutes approximately 0.5% 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 4,991,000 Shares in the aggregate, which constitutes approximately 8.1% 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 4,991,000 Shares, which constitutes approximately 8.1% of the outstanding Shares. WEO Because of his position as a control person of SPO Advisory Corp., WEO may, pursuant to Rule 13d-3 of the Act, be deemed to be the beneficial owner of 4,991,000 Shares, which constitutes approximately 8.1% 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 4,991,000 Shares, which constitutes approximately 8.1% 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. (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 4,692,500 Shares.

Page 12 of 35 pages 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 4,692,500 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 298,500 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 298,500 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 4,991,000 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 4,991,000 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 4,991,000 Shares held by SPO and SFP in the aggregate. 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 4,991,000 Shares held by SPO and SFP in the aggregate. (c) Within the past 60 days of the date of this statement, Reporting Persons purchased Shares in open market transactions as set forth on Schedule I attached hereto.

Page 13 of 35 pages 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)

Page 14 of 35 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 September 14, 2005 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) (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.

Page 15 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 8/29/2005 Buy 94 33.15 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,692 33.20 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 376 33.21 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,410 33.22 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,786 33.23 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 94 33.24 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 188 33.25 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 846 33.26 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,034 33.27 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,128 33.28 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 752 33.31 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 2,444 33.32 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,222 33.33 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 752 33.34 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 94 33.35 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,222 33.36 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,880 33.37 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,974 33.39 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,222 33.40 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 188 33.41 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 940 33.42 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 846 33.43 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 1,974 33.45 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 2,068 33.46 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 658 33.47 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 846 33.48 Open Market/Broker SPO Partners II, L.P. 8/29/2005 Buy 752 33.49 Open Market/Broker

Page 16 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 8/29/2005 Buy 1,518 33.50 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 6 33.15 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 108 33.20 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 24 33.21 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 90 33.22 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 114 33.23 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 6 33.24 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 12 33.25 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 54 33.26 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 66 33.27 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 72 33.28 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 48 33.31 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 156 33.32 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 78 33.33 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 48 33.34 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 6 33.35 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 78 33.36 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 120 33.37 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 126 33.39 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 78 33.40 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 12 33.41 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 60 33.42 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 54 33.43 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 126 33.45 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 132 33.46 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 42 33.47 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 54 33.48 Open Market/Broker

Page 17 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 8/29/2005 Buy 48 33.49 Open Market/Broker San Francisco Partners, L.P. 8/29/2005 Buy 82 33.50 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 2,068 32.95 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,410 32.96 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 94 33.00 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,974 33.01 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 564 33.02 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 2,444 33.03 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 846 33.05 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 282 33.06 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,034 33.07 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,316 33.08 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 940 33.09 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 658 33.14 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 94 33.15 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 470 33.16 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 470 33.17 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 2,068 33.18 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,786 33.19 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 29,422 33.20 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,410 33.21 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 2,256 33.22 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 3,666 33.23 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,316 33.24 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,504 33.25 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,598 33.26 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,880 33.27 Open Market/Broker

Page 18 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 8/30/2005 Buy 564 33.28 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 94 33.29 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 188 33.30 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 188 33.37 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 376 33.38 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 1,128 33.39 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 752 33.41 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 188 33.42 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 470 33.44 Open Market/Broker SPO Partners II, L.P. 8/30/2005 Buy 282 33.48 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 132 32.95 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 90 32.96 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 6 33.00 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 126 33.01 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 36 33.02 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 156 33.03 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 54 33.05 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 18 33.06 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 66 33.07 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 84 33.08 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 60 33.09 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 42 33.14 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 6 33.15 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 30 33.16 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 30 33.17 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 132 33.18 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 114 33.19 Open Market/Broker

Page 19 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 8/30/2005 Buy 1,878 33.20 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 90 33.21 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 144 33.22 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 234 33.23 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 84 33.24 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 96 33.25 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 102 33.26 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 120 33.27 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 36 33.28 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 6 33.29 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 12 33.30 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 12 33.37 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 24 33.38 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 72 33.39 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 48 33.41 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 12 33.42 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 30 33.44 Open Market/Broker San Francisco Partners, L.P. 8/30/2005 Buy 18 33.48 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 3,948 32.90 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 1,222 32.91 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 470 32.92 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 470 32.93 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 470 32.94 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 33,464 32.95 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 376 32.96 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 1,974 32.97 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 3,478 32.98 Open Market/Broker

Page 20 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 8/31/2005 Buy 1,410 32.99 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 16,638 33.00 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 376 33.01 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 188 33.02 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 376 33.03 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 188 33.04 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 752 33.05 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 564 33.06 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 2,914 33.07 Open Market/Broker SPO Partners II, L.P. 8/31/2005 Buy 922 33.09 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 252 32.90 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 78 32.91 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 30 32.92 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 30 32.93 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 30 32.94 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 2,136 32.95 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 24 32.96 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 126 32.97 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 222 32.98 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 90 32.99 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 1,062 33.00 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 24 33.01 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 12 33.02 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 24 33.03 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 12 33.04 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 48 33.05 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 36 33.06 Open Market/Broker

Page 21 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 8/31/2005 Buy 186 33.07 Open Market/Broker San Francisco Partners, L.P. 8/31/2005 Buy 78 33.09 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 282 32.93 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 564 32.98 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 1,410 33.00 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 94 33.35 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 282 33.36 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 1,222 33.37 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 1,316 33.38 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 282 33.41 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 658 33.43 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 1,974 33.44 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 564 33.45 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 1,880 33.46 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 4,324 33.47 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 1,598 33.49 Open Market/Broker SPO Partners II, L.P. 9/1/2005 Buy 4,650 33.50 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 18 32.93 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 36 32.98 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 90 33.00 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 6 33.35 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 18 33.36 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 78 33.37 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 84 33.38 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 18 33.41 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 42 33.43 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 126 33.44 Open Market/Broker

Page 22 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 9/1/2005 Buy 36 33.45 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 120 33.46 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 276 33.47 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 102 33.49 Open Market/Broker San Francisco Partners, L.P. 9/1/2005 Buy 250 33.50 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 940 32.84 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 32.86 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 282 32.87 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 2,444 32.88 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 2,256 32.89 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 4,042 32.90 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 2,632 32.91 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 4,136 32.92 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 3,008 32.93 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 1,786 32.94 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 2,632 32.95 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 2,350 32.96 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 3,478 32.97 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 1,598 32.98 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 752 32.99 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 2,350 33.00 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 376 33.01 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 564 33.02 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 188 33.03 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 282 33.06 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 470 33.07 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 33.14 Open Market/Broker

Page 23 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 9/2/2005 Buy 94 33.15 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 188 33.18 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 33.19 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 33.22 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 33.24 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 33.32 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 33.37 Open Market/Broker SPO Partners II, L.P. 9/2/2005 Buy 94 33.44 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 60 32.84 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 32.86 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 18 32.87 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 156 32.88 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 144 32.89 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 258 32.90 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 168 32.91 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 264 32.92 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 192 32.93 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 114 32.94 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 168 32.95 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 150 32.96 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 222 32.97 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 102 32.98 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 48 32.99 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 150 33.00 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 24 33.01 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 36 33.02 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 12 33.03 Open Market/Broker

Page 24 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 9/2/2005 Buy 18 33.06 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 30 33.07 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.14 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.15 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 12 33.18 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.19 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.22 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.24 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.32 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.37 Open Market/Broker San Francisco Partners, L.P. 9/2/2005 Buy 6 33.44 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 94 32.75 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 2,350 32.76 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 376 32.78 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 3,102 32.79 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 1,128 32.80 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 1,786 32.81 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 32.82 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 1,786 32.83 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 564 32.87 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 12,126 32.88 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 4,700 33.00 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 33.06 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 33.07 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 33.08 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 33.09 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 282 33.10 Open Market/Broker

Page 25 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 9/6/2005 Buy 376 33.12 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 33.13 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 470 33.14 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 564 33.15 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 33.16 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 376 33.17 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 470 33.18 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 1,880 33.19 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 282 33.20 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 188 33.21 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 658 33.22 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 846 33.23 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 1,222 33.24 Open Market/Broker SPO Partners II, L.P. 9/6/2005 Buy 658 33.25 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 6 32.75 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 150 32.76 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 24 32.78 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 198 32.79 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 72 32.80 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 114 32.81 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 12 32.82 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 114 32.83 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 36 32.87 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 774 32.88 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 300 33.00 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 12 33.06 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 12 33.07 Open Market/Broker

Page 26 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 9/6/2005 Buy 12 33.08 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 12 33.09 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 18 33.10 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 24 33.12 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 12 33.13 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 30 33.14 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 36 33.15 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 12 33.16 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 24 33.17 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 30 33.18 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 120 33.19 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 18 33.20 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 12 33.21 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 42 33.22 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 54 33.23 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 78 33.24 Open Market/Broker San Francisco Partners, L.P. 9/6/2005 Buy 42 33.25 Open Market/Broker SPO Partners II, L.P. 9/7/2005 Buy 376 32.86 Open Market/Broker SPO Partners II, L.P. 9/7/2005 Buy 376 32.89 Open Market/Broker SPO Partners II, L.P. 9/7/2005 Buy 188 32.93 Open Market/Broker SPO Partners II, L.P. 9/7/2005 Buy 93,960 33.00 Open Market/Broker San Francisco Partners, L.P. 9/7/2005 Buy 24 32.86 Open Market/Broker San Francisco Partners, L.P. 9/7/2005 Buy 24 32.89 Open Market/Broker San Francisco Partners, L.P. 9/7/2005 Buy 12 32.93 Open Market/Broker San Francisco Partners, L.P. 9/7/2005 Buy 6,040 33.00 Open Market/Broker SPO Partners II, L.P. 9/8/2005 Buy 15,980 33.00 Open Market/Broker SPO Partners II, L.P. 9/8/2005 Buy 10,810 33.05 Open Market/Broker

Page 27 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 9/8/2005 Buy 94 33.08 Open Market/Broker SPO Partners II, L.P. 9/8/2005 Buy 1,504 33.09 Open Market/Broker SPO Partners II, L.P. 9/8/2005 Buy 6,412 33.10 Open Market/Broker San Francisco Partners, L.P. 9/8/2005 Buy 1,020 33.00 Open Market/Broker San Francisco Partners, L.P. 9/8/2005 Buy 690 33.05 Open Market/Broker San Francisco Partners, L.P. 9/8/2005 Buy 6 33.08 Open Market/Broker San Francisco Partners, L.P. 9/8/2005 Buy 96 33.09 Open Market/Broker San Francisco Partners, L.P. 9/8/2005 Buy 388 33.10 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 282 32.99 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 188 33.02 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 658 33.03 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 94 33.05 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 94 33.06 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 846 33.07 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 658 33.08 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 1,316 33.09 Open Market/Broker SPO Partners II, L.P. 9/9/2005 Buy 2,164 33.10 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 18 32.99 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 12 33.02 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 42 33.03 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 6 33.05 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 6 33.06 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 54 33.07 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 42 33.08 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 84 33.09 Open Market/Broker San Francisco Partners, L.P. 9/9/2005 Buy 136 33.10 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 376 32.66 Open Market/Broker

Page 28 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 9/12/2005 Buy 940 32.67 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 658 32.68 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 470 32.70 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 94 32.73 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 1,034 32.75 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 94 32.78 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 564 32.80 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 470 32.90 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 188 32.91 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 1,880 32.92 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 188 32.94 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 846 32.95 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 564 32.96 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 2,444 32.97 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 1,598 32.98 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 2,350 32.99 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 20,210 33.00 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 188,282 33.01 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 1,692 33.02 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 9,400 33.03 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 3,384 33.04 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 17,954 33.05 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 21,620 33.10 Open Market/Broker SPO Partners II, L.P. 9/12/2005 Buy 4,700 33.18 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 24 32.66 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 60 32.67 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 42 32.68 Open Market/Broker

Page 29 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 9/12/2005 Buy 30 32.70 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 6 32.73 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 66 32.75 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 6 32.78 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 36 32.80 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 30 32.90 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 12 32.91 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 120 32.92 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 12 32.94 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 54 32.95 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 36 32.96 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 156 32.97 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 102 32.98 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 150 32.99 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 1,290 33.00 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 12,018 33.01 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 108 33.02 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 600 33.03 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 216 33.04 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 1,146 33.05 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 1,380 33.10 Open Market/Broker San Francisco Partners, L.P. 9/12/2005 Buy 300 33.18 Open Market/Broker

Page 30 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 9/13/2005 Buy 1,034 32.03 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 564 32.04 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 3,196 32.05 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,786 32.06 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,504 32.07 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,692 32.08 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 282 32.09 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 2,444 32.11 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,034 32.12 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,222 32.13 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 4,888 32.14 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 5,828 32.15 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,222 32.16 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 6,204 32.17 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,692 32.24 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 940 32.26 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 2,538 32.27 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,598 32.28 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 4,136 32.29 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 13,066 32.30 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 2,162 32.31 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 94 32.33 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,034 32.34 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 4,888 32.35 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 3,854 32.36 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 846 32.37 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,316 32.38 Open Market/Broker

Page 31 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 9/13/2005 Buy 1,128 32.39 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 2,444 32.40 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 376 32.41 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 188 32.45 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 470 32.58 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 282 32.60 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 376 32.61 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 846 32.62 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 1,222 32.64 Open Market/Broker SPO Partners II, L.P. 9/13/2005 Buy 34,404 32.65 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 66 32.03 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 36 32.04 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 204 32.05 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 114 32.06 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 96 32.07 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 108 32.08 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 18 32.09 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 156 32.11 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 66 32.12 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 78 32.13 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 312 32.14 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 372 32.15 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 78 32.16 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 396 32.17 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 108 32.24 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 60 32.26 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 162 32.27 Open Market/Broker

Page 32 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 9/13/2005 Buy 102 32.28 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 264 32.29 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 834 32.30 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 138 32.31 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 6 32.33 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 66 32.34 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 312 32.35 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 246 32.36 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 54 32.37 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 84 32.38 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 72 32.39 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 156 32.40 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 24 32.41 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 12 32.45 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 30 32.58 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 18 32.60 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 24 32.61 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 54 32.62 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 78 32.64 Open Market/Broker San Francisco Partners, L.P. 9/13/2005 Buy 2,196 32.65 Open Market/Broker

Page 33 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- SPO Partners II, L.P. 9/14/2005 Buy 475 32.00 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 2,090 32.01 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 6,745 32.02 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 8,930 32.03 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 5,510 32.04 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 6,840 32.05 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 570 32.06 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 2,660 32.07 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 1,710 32.08 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 2,850 32.09 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 1,425 32.10 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 1,805 32.11 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 1,900 32.12 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 2,660 32.13 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 4,940 32.14 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 5,320 32.15 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 5,700 32.16 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 1,520 32.17 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 855 32.18 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 2,660 32.19 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 18,335 32.20 Open Market/Broker SPO Partners II, L.P. 9/14/2005 Buy 9,500 32.23 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 25 32.00 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 110 32.01 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 355 32.02 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 470 32.03 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 290 32.04 Open Market/Broker

Page 34 of 35 pages SCHEDULE I TO SCHEDULE 13D FOR SPO PARTNERS II, L.P. DATE OF PRICE PER WHERE/HOW TRANSACTION REPORTING PERSON TRANSACTION TYPE NUMBER OF SHARES SHARE ($) EFFECTED - ---------------------------- ---------- ---- ---------------- --------- ---------------------- San Francisco Partners, L.P. 9/14/2005 Buy 360 32.05 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 30 32.06 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 140 32.07 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 90 32.08 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 150 32.09 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 75 32.10 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 95 32.11 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 100 32.12 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 140 32.13 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 260 32.14 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 280 32.15 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 300 32.16 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 80 32.17 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 45 32.18 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 140 32.19 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 965 32.20 Open Market/Broker San Francisco Partners, L.P. 9/14/2005 Buy 500 32.23 Open Market/Broker

Page 35 of 35 pages EXHIBIT INDEX EXHIBIT DOCUMENT DESCRIPTION PAGE NO. - ------- ------------------------------------ -------- A Agreement Pursuant to Rule 13d-1(k) 1

                                    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: September 14, 2005                  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)

                                           (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.