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                                                                    EXHIBIT 10.4


                            EQUISTAR CHEMICALS, LP

                     EXECUTIVE SUPPLEMENTARY SAVINGS PLAN

                          EDITION OF JANUARY 1, 2000
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                               TABLE OF CONTENTS

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Section 1. Intent of Plan.......................................... 1
Section 2. Effective Date of Plan.................................. 1

Section 3. Definitions............................................. 1
  3.1. "Administrative Committee" or "Committee"................... 1
  3.2. "Base Pay".................................................. 1
  3.3. "Company"................................................... 1
  3.4. "Employee".................................................. 1
  3.5. "Plan Year"................................................. 1

Section 4. Costs of Plan........................................... 2

Section 5. Eligibility for Benefits................................ 2

Section 6. Amount of Benefit....................................... 2

Section 7. Crediting of Benefit.................................... 2

Section 8. Time of Payment of Benefit.............................. 2

Section 9. Death Benefits.......................................... 2

Section 10. Administration......................................... 2
  10.1. Rules of Conduct........................................... 2
  10.2. Legal, Accounting, Clerical and Other Services............. 2
  10.3. Interpretation of Provisions............................... 3
  10.4. Records of Administration.................................. 3
  10.5. Denial of Claim............................................ 3
  10.6. Liability of Committee..................................... 3

Section 11. Facility of Payment and Lapse of Benefits.............. 3
  11.1. Provision for Incapacity................................... 3
  11.2. Payments or Deposits....................................... 3

Section 12. General Provisions..................................... 4
  12.1. Unfunded Benefit Plan...................................... 4
  12.2. Payments and Benefits Not Assignable....................... 4
  12.3. No Right of Employment..................................... 4
  12.4. Adjustments................................................ 4

Section 13. Amendments and Discontinuance.......................... 4
  13.1. Amendment of Plan.......................................... 4
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  13.2. Termination................................................ 4
  13.3. Effect of Amendment or Termination......................... 4
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                            EQUISTAR CHEMICALS, LP
                     EXECUTIVE SUPPLEMENTARY SAVINGS PLAN

                          Section 1. Intent of Plan.

     1.1. This Plan is intended to provide an annual benefit, in accordance with
its provisions to that select group of management or highly compensated
employees whose participation in the Equistar Chemicals, LP Savings and
Investment Plan is limited.

                      Section 2. Effective Date of Plan.

     2.1. This Plan shall be effective as of January 1, 2000.

                            Section 3. Definitions

     3.1. "Administrative Committee" or "Committee" means the Benefits
Administrative Committee appointed by the Partnership Governance Committee of
the Company.

     3.2. "Base Pay" means an Employee's regular wages or salary, as determined
by the Company, excluding extra pay, such as bonuses, or other supplementary
allowances;

     3.3. "Company" means Equistar Chemicals, LP and any of its subsidiaries or
affiliates whose employees are included in this Plan upon authorization of the
Partnership Governance Committee of Equistar Chemicals, LP.

     3.4. "Employee" means any person who:

            (a)   is regularly employed by the Company on a full time or part
                  time basis;

            and

            (b)   either:

                  (i)  is a member of that select group of management or highly
                       compensated employees on the executive payroll; or

                  (ii) is an employee with an annualized Base Pay no less than
                       $160,000;

                  and

            (c)   has been excluded from making Savings Contributions and from
                  receiving Company Contributions under the Equistar Chemicals,
                  LP Savings and Investment Plan.

     3.5. "Plan Year" means the calendar year.

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                           Section 4. Costs of Plan.

     4.1.  The Company shall bear all costs of this Plan, including its
administration, and no Employee contributions shall be required or permitted.

                     Section 5. Eligibility for Benefits.

     5.1.  Each person who qualifies as an Employee under Paragraph 3.4 for all
or any part of a Plan Year shall participate in the Plan for that portion of the
Plan Year.

                         Section 6. Amount of Benefit.

     6.1.  The amount of an Employee's benefit for each Plan Year shall be equal
to the maximum Company Contribution under the Equistar Chemicals, LP Savings and
Investment Plan, assuming no limitations on contributions imposed by Section 415
or any other Sections of the Code during the Plan Year.

                       Section 7. Crediting of Benefit.

     7.1.  The Administrative Committee shall determine the amount of benefit to
be credited to an Employee for a Plan Year within 30 days after the end of the
Plan Year or 30 days after the Employee's termination of employment, whichever
occurs earlier.

                    Section 8. Time of Payment of Benefit.

     8.1.  An Employee shall be paid the benefit to which the Employee is
entitled for a Plan Year in a single cash payment no later than 30 days
following the date the Company credits the benefit, unless the benefit has been
deferred under the Equistar Chemicals, LP Executive Deferral Plan.

                          Section 9. Death Benefits.

     9.1.  If an Employee dies prior to payment of the benefit due under the
Plan, the benefit shall be paid as soon as practicable following the Employee's
death to the Employee's most recently designated beneficiary or beneficiaries.
The beneficiary must be designated in writing on a form approved by the
Committee and must be accepted by the Plan prior to the Employee's death. If no
designation has been made, or if all designated beneficiaries have died before
the Employee, the benefit shall be paid to the Employee's estate.

                          Section 10. Administration.

     10.1. Rules of Conduct. The Administrative Committee shall adopt rules to
conduct its business and the Plan's administration as it considers desirable,
provided they do not conflict with the Plan's provisions.

     10.2. Legal, Accounting, Clerical and Other Services. The Administrative
Committee may authorize one or more of its members or any agent to act on its
behalf and may contract for

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legal, accounting, clerical and other services to carry out this Plan. The
Company shall pay all expenses of the Administrative Committee.

     10.3. Interpretation of Provisions. The Administrative Committee shall have
the exclusive right and discretionary authority to interpret the provisions of
this Plan and to decide questions arising in its administration including, but
not limited to, questions of eligibility for Plan benefits. Administrative
Committee's decisions and interpretations shall be final, binding and conclusive
on the Company, its Employees and all other persons.

     10.4. Records of Administration. The Administrative Committee shall
maintain Plan administration records. These records are subject to audit by the
Company.

     10.5. Denial of Claim. The Administrative Committee shall provide adequate
written notice to any Employee or beneficiary whose claim for Plan benefits has
been denied, setting forth the specific reasons for the denial. The
Administrative Committee will give the Employee or beneficiary an opportunity
for a full and fair review of the decision denying the claim. The Employee or
beneficiary shall have 60 days from the date of the notice denying the claim to
request a full and fair review.

     10.6. Liability of Committee. No member of the Administrative Committee
shall be liable for any action taken in good faith or for exercising any power
given to the Administrative Committee or for the actions of other Committee
members.

            Section 11. Facility of Payment and Lapse of Benefits.

     11.1. Provision for Incapacity. If the Administrative Committee deems that
any person entitled to receive any Plan payment is incapable of receiving or
disbursing the payment because of minority, illness or infirmity, mental
incompetency, or incapacity of any kind, the Committee, in its sole discretion,
may take any one or more of the following actions: it may apply the payment
directly for the person's comfort, support and maintenance; it may reimburse any
other person for support supplied to the person entitled to receive any payment;
or it may pay the payment to any other person the Committee selects to disburse
the payment for the comfort, support and maintenance of the person entitled to
the payment, including, without limitation, to any relative who has wholly or
partially undertaken the expense of the person's comfort, care and maintenance,
or any institution which is caring for or which has custody of the person
entitled to the payment. The Administrative Committee, in its sole discretion,
may deposit any payment due to a minor to the minor's credit in any savings or
commercial bank of the Committee's choice.

     11.2. Payments or Deposits. Payments or deposits made under this Section 11
shall completely discharge, to the extent of the payment, all liability of the
Administrative Committee, the Company and this Executive Supplementary Savings
Plan under this Plan or otherwise. A person's receipt of any payment,
distribution or deposit shall be a complete acquittance and there shall be no
liability to see to the application of any payments, distributions or deposits
made.

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                        Section 12. General Provisions.

     12.1. Unfunded Benefit Plan. This Executive Supplementary Savings Plan is
intended to be an unfunded plan maintained primarily for the purpose of
providing deferred compensation to a select group of management or highly
compensated employees.

     12.2. Payments and Benefits Not Assignable. Benefits under this Plan are
not assignable, transferable or subject to alienation by Employees. Likewise,
payments are not subject to attachment by creditors of, or through legal process
against, the Company, the Administrative Committee, or any Employee.

     12.3. No Right of Employment. Plan provisions shall not give an Employee
the right to be retained in the Company's service nor shall this Plan or any
action taken under it, be construed as an employment contract.

     12.4. Adjustments. At the Company's request, the Administrative Committee,
may adjust an Employee's benefit under this Plan or make other adjustments with
respect to the Employee as required to correct administrative errors or provide
uniform treatment of Employees in a manner consistent with this Plan's intent
and purpose.

                  Section 13. Amendments and Discontinuance.

     13.1. Amendment of Plan. This Plan may be amended from time to time by the
Partnership Governance Committee of the Company.

     13.2. Termination. The Partnership Governance Committee of the Company
reserves the right to terminate this Plan at any time.

     13.3. Effect of Amendment or Termination. No Plan amendment or Plan
termination may adversely affect the benefit payable to any Employee entitled to
receive benefits under this Plan prior to the effective date of the amendment or
termination.

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