Document:

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                                                                EXHIBIT 10.10(b)

           SECOND AMENDMENT TO LYONDELL ASSET CONTRIBUTION AGREEMENT
           ---------------------------------------------------------

     This Second Amendment to Lyondell Asset Contribution Agreement (this
"Second Amendment"), dated as of September 30, 2001, is entered into by and
among Lyondell Chemical Company, a Delaware corporation (the "Contributor"),
Lyondell Petrochemical LP Inc., a Delaware corporation (the "Contributing
Partner") and Equistar Chemicals, LP, a Delaware limited partnership (the
"Partnership").

                                   RECITALS:
                                   --------

     A.   The Contributor (as successor to Lyondell Petrochemical Company), the
Contributing Partner and the Partnership are parties to that certain Asset
Contribution Agreement, dated as of December 1, 1997, as amended by that certain
First Amendment to Lyondell Asset Contribution Agreement, dated as of May 15,
1998 (such agreement, as amended by the First Amendment, herein called the
"Asset Contribution Agreement").

     B.   Following execution of the Asset Contribution Agreement, the
Contributor, the Contributing Partner and the Partnership (the "Parties" and
each individually, a "Party") have agreed to certain amendments clarifying the
treatment of, and procedures pertaining to the management of, certain claims
arising under the Asset Contribution Agreement.

     C.   Simultaneously, and as an integral part of the resolution of the
matters referenced herein, (i) the Partnership and certain affiliates of
Occidental Petroleum Corporation have agreed to make certain amendments pursuant
to that certain First Amendment to Occidental Asset Contribution Agreement dated
as of September 30, 2001 (the "Occidental First Amendment") and (ii) the
Partnership and certain affiliates of Millennium Petrochemicals, Inc. have
agreed to settle certain claims and make certain amendments pursuant to that
certain Second Amendment to Millennium Asset Contribution Agreement dated as of
September 30, 2001 (the "Millennium Second Amendment").

     D.   Accordingly, the Parties desire to amend the Asset Contribution
Agreement on the terms set forth herein. Capitalized terms used and not
otherwise defined herein shall have the meanings given such terms in the Asset
Contribution Agreement. All section references in this Second Amendment are
intended to refer to provisions contained in the Asset Contribution Agreement.

     NOW THEREFORE, in consideration of the premises and of the mutual covenants
of the Parties hereto, it is hereby agreed that the Asset Contribution Agreement
is hereby amended as follows:

                                       1
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     Section 1.     Assumption of Liabilities.
                    -------------------------

     (a)  Section 2.5(a)(vi) is hereby amended and restated as follows:

          (vi)      Third Party Claims (including De Minimis Claims) that are
     related to Pre-Closing Contingent Liabilities and that are first asserted
     seven years or more after the Closing Date.

     (b)  The word "and" is hereby deleted from the end of Section 2.5(a)(x) and
          added to the end of Section 2.5(a)(xi).

     (c)  A new Section 2.5(a)(xii) is hereby added as follows:

          (xii)     Pre-Closing Contingent Liabilities that do not involve a
     Third Party Claim and De Minimis Claims first asserted against the
     Partnership (and not the Contributor) within seven years after the Closing
     Date.

     Section 2.     Excluded Liabilities.  Section 2.6(i) is hereby amended and
                    --------------------
 restated as follows:

          (i)       Any Pre-Closing Contingent Liability that is not an Assumed
     Liability, including any De Minimis Claim that is first asserted against
     Contributor and the Partnership, jointly, within seven years after the
     Closing Date.

     Section 3.     Lowest Cost Response.  The definition of "Lowest Cost
                    --------------------
Response" is hereby amended to delete the phrase "Chemical Substances" in the
first sentence and replace it with the word "condition."

     Section 4.     Effectiveness of this Second Amendment. This Second
                    --------------------------------------
Amendment shall be effective from and after the date hereof except as expressly
provided with respect to certain disputes described in the Millennium Second
Amendment; provided, however, that the execution and delivery of the Occidental
First Amendment and the Millennium Second Amendment shall be conditions to the
effectiveness of this Second Amendment. Except as amended by this Second
Amendment, all of the terms and provisions of the Asset Contribution Agreement
shall remain in full force and effect among the Parties from and after the date
hereof.

     Section 5.     Counterparts.  This Second Amendment may be executed in any
                    ------------
number of counterparts, each of which shall be deemed an original and all of
which together shall be deemed one and the same instrument.

     Section 6.     APPLICABLE LAW.  THIS SECOND AMENDMENT SHALL BE GOVERNED BY,
                    --------------
AND CONTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF DELAWARE EXCLUDING
CONFLICTS OF LAW PRINCIPLES OF SUCH JURISDICTION, EXCEPT TO THE EXTENT SUCH
MATTERS ARE MANDATORILY

                                       2
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SUBJECT TO THE LAWS OF ANOTHER JURISDICTION PURSUANT TO THE LAWS OF SUCH OTHER
JURISDICTION.

                 [Remainder of Page Intentionally Left Blank]

                                       3
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     IN WITNESS WHEREOF, the Parties have executed and delivered this Second
Amendment as of the date first above written.

                                        LYONDELL CHEMICAL COMPANY,
                                        a Delaware corporation.

                                        By: /s/ Dan F. Smith
                                           -------------------------------
                                        Name: Dan F. Smith
                                        Title: President & Chief Executive
                                               Officer

                                        LYONDELL PETROCHEMICAL LP INC.,
                                        a Delaware corporation

                                        By: /s/ Gerald A. O'Brien
                                           -------------------------------
                                        Name: Gerald A. O'Brien
                                        Title: Vice President & General Counsel

                                        EQUISTAR CHEMICALS, LP,
                                        a Delaware limited partnership

                                        By: /s/ Eugene R. Allspach
                                           -------------------------------
                                        Name: Eugene R. Allspach
                                        Title: President & Chief Operating
                                               Officer

 [Signature Page to Second Amendment To Lyondell Asset Contribution Agreement]

                                       4<PAGE>

                                                                EXHIBIT 10.11(b)

          SECOND AMENDMENT TO MILLENNIUM ASSET CONTRIBUTION AGREEMENT
          -----------------------------------------------------------

         This Second Amendment to Millennium Asset Contribution Agreement (this
"Second Amendment"), dated as of September 30, 2001, is entered into by and
among Millennium Petrochemicals Inc., a Virginia corporation (the
"Contributor"), Millennium Petrochemicals LP LLC, a Delaware limited liability
company (the "Contributing Partner") and Equistar Chemicals, LP, a Delaware
limited partnership (the "Partnership").

                                   RECITALS:
                                   --------

         A. The Contributor, the Contributing Partner and the Partnership are
parties to that certain Asset Contribution Agreement, dated as of December 1,
1997, as amended by that certain First Amendment to Millennium Asset
Contribution Agreement, dated as of May 15, 1998 (such agreement, as amended by
the First Amendment, herein called the "Asset Contribution Agreement").

         B. Following execution of the Asset Contribution Agreement, the
Contributor, the Contributing Partner and the Partnership (the "Parties" and
each individually, a "Party") have agreed to certain amendments clarifying the
treatment of, and procedures pertaining to the management of, certain claims
arising under the Asset Contribution Agreement.

         C. Simultaneously, and as an integral part of the resolution of the
matters referenced herein, (i) the Partnership and certain affiliates of
Occidental Petroleum Corporation have agreed to make certain amendments pursuant
to that certain First Amendment to Occidental Asset Contribution Agreement dated
as of September 30, 2001 (the "Occidental First Amendment") and (ii) the
Partnership and certain affiliates of Lyondell Chemical Company have agreed to
settle certain claims and make certain amendments pursuant to that certain
Second Amendment to Lyondell Asset Contribution Agreement dated as of September
30, 2001 (the "Lyondell Second Amendment").

         D. Accordingly, the Parties desire to amend the Asset Contribution
Agreement on the terms set forth herein. Capitalized terms used and not
otherwise defined herein shall have the meanings given such terms in the Asset
Contribution Agreement. All section references in this Second Amendment are
intended to refer to provisions contained in the Asset Contribution Agreement.

         NOW THEREFORE, in consideration of the premises and of the mutual
covenants of the Parties hereto, it is hereby agreed that the Asset Contribution
Agreement is hereby amended as follows:

         Section 1. Seven Year PCCL Claims. In settlement of a dispute
         ---------------------------------
concerning treatment of certain claims under the Asset Contribution Agreement,
the Parties hereby agree that the liabilities set forth on Exhibit A, in the
                                                           ---------
amounts specified therein, shall be deemed to be Seven Year PCCL Claims and such
claims shall thereby be fully and finally resolved.

                                       1
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         Section 2.      Assumption of Liabilities.
                         -------------------------

         (a)      Section 2.5(a)(vi) is hereby amended and restated as follows:

                  (vi)   Third Party Claims (including De Minimis Claims) that
         are related to Pre-Closing Contingent Liabilities and that are first
         asserted seven years or more after the Closing Date.

         (b)      The word "and" is hereby deleted from the end of Section
2.5(a)(x) and added to the end of Section 2.5(a)(xi).

         (c)      A new Section 2.5(a)(xii) is hereby added as follows:

                  (xii)  Pre-Closing Contingent Liabilities that do not involve
         a Third Party Claim and De Minimis Claims first asserted against the
         Partnership (and not the Contributor) within seven years after the
         Closing Date.

         Section 3.      Excluded Liabilities. Section 2.6(i) is hereby amended
                         --------------------
and restated as follows:

                  (i)    Any Pre-Closing Contingent Liability that is not an
         Assumed Liability, including any De Minimis Claim that is first
         asserted against Contributor and the Partnership, jointly, within seven
         years after the Closing Date.

         Section 4.      Lowest Cost Response.  The definition of "Lowest Cost
                         --------------------
Response" is hereby amended to delete the phrase "Chemical Substances" in the
first sentence and replace it with the word "condition."

         Section 5.      Effectiveness of this Second Amendment. This Second
                         --------------------------------------
Amendment shall be effective from and after the date hereof except as
specifically provided in Section 1 hereof; provided, however, that the execution
and delivery of the Occidental First Amendment and the Lyondell Second Amendment
shall be conditions to the effectiveness of this Second Amendment. Except as
amended by this Second Amendment, all of the terms and provisions of the Asset
Contribution Agreement shall remain in full force and effect among the Parties
from and after the date hereof.

         Section 6.      Counterparts.  This Second Amendment may be executed in
                         ------------
any number of counterparts, each of which shall be deemed an original and all of
which together shall be deemed one and the same instrument.

         Section 7. APPLICABLE LAW. THIS SECOND AMENDMENT SHALL BE GOVERNED BY,
                    --------------
AND CONTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF DELAWARE EXCLUDING
CONFLICTS OF LAW PRINCIPLES OF SUCH

                                       2
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JURISDICTION, EXCEPT TO THE EXTENT SUCH MATTERS ARE MANDATORILY SUBJECT TO THE
LAWS OF ANOTHER JURISDICTION PURSUANT TO THE LAWS OF SUCH OTHER JURISDICTION.

                 [Remainder of Page Intentionally Left Blank]

                                       3
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         IN WITNESS WHEREOF, the Parties have executed and delivered this Second
Amendment as of the date first above written.

                                     MILLENNIUM PETROCHEMICALS INC.,
                                     a Virginia corporation.

                                     By: /s/ C. William Carmean
                                         -----------------------------------
                                     Name:   C. William Carmean
                                     Title:  Vice President-Legal

                                     MILLENNIUM PETROCHEMICALS LP LLC,
                                     a Delaware limited liability company

                                     By: /s/ C. William Carmean
                                         ---------------------------------
                                     Name:   C. William Carmean
                                     Title:  Vice President-Legal

                                     EQUISTAR CHEMICALS, LP,
                                     a Delaware limited partnership

                                     By: /s/ Eugene R. Allspach
                                         ---------------------------------
                                     Name:   Eugene R. Allspach
                                     Title:  President and Chief Operating
                                             Officer

[Signature Page to Second Amendment To Millennium Asset Contribution Agreement]

                                       4
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                                   EXHIBIT A
                                   ---------

                            Seven Year PCCL Claims

The following Claims made by Equistar against Millennium shall be included as
Seven Year PCCL Claims for an aggregate amount of $1,757,131:

1.    Due diligence items from asset sale at Heath.

2.    Old waste oil sump at Heath.

3.    Due diligence items from asset sale at Crockett.

4.    Pellet and powder controls at La Porte.

5.    AB compressor controls at La Porte.

6.    Self-closing gates at La Porte.

7.    Quench tower relief project at La Porte.

8.    AB2/AB3 compliance projects at La Porte.

9.    Complex-wide emergency alarm and radio at La Porte.

10.   S-1 feed alternative heat (Petro FBO modifications) at La Porte.

11.   Plant alarm replacement at La Porte.

12.   VOM emission controls and Ohio permits at Fairport Harbor.

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