<PAGE>
 
                                                                   EXHIBIT 10.34


                                                 EXHIBIT B TO FIRST AMENDMENT TO
                                                    MASTER TRANSACTION AGREEMENT




                         ASSET CONTRIBUTION AGREEMENT



                                    BETWEEN



                                [CONTRIBUTOR],



                            [CONTRIBUTING PARTNER]



                                      AND



                            EQUISTAR CHEMICALS, LP



                           DATED: ____________, 1997
<PAGE>
 
                               TABLE OF CONTENTS
                               -----------------


 
                                                                           PAGE
                                                                           ----

SECTION 1  DEFINITIONS....................................................   1

SECTION 2  CONTRIBUTION OF ASSETS; ASSUMPTION OF CERTAIN
           LIABILITIES....................................................   8
     2.1   Transfer of Assets.............................................   8
     2.2   Excluded Assets................................................  10
     2.3   Instruments of Conveyance and Assignment.......................  11
     2.4   Further Assurances.............................................  12
     2.5   Assumption of Liabilities......................................  13
     2.6   Excluded Liabilities...........................................  14
     2.7   Technology and Trademark Licenses..............................  14
     2.8   Employee Matters...............................................  14
     2.9   Joint Contracts................................................  16
 
SECTION 3  REPRESENTATIONS AND WARRANTIES OF THE CONTRIBUTOR..............  17
     3.1   Due Organization; Good Standing and Power......................  17
     3.2   Authorization and Validity of Agreements.......................  17
     3.3   No Consents Required; No Conflict with Instruments to which the
           Contributor is a Party.........................................  17
     3.4   Employee Benefits..............................................  18
     3.5   Title to Assets; Absence of Liens and Encumbrances; Leases.....  19
     3.6   Title Matters; Defects in Improvements.........................  20
     3.7   Working Capital................................................  20
     3.8   Technology and Similar Rights..................................  20
     3.9   Government Licenses, Permits and Related Approvals.............  20
     3.10  All Necessary Assets...........................................  21
     3.11  Conduct of Business in Compliance with Regulatory and
           Contractual Requirements.......................................  21
     3.12  Legal Proceedings..............................................  21
     3.13  Consents.......................................................  21
     3.14  Tax Matters....................................................  21
     3.15  [Reserved].....................................................  21
     3.16  HSE Matters....................................................  21
     3.17  Investigation to Acquire Knowledge.............................  22
 
SECTION 4  REPRESENTATIONS AND WARRANTIES OF THE PARTNERSHIP..............  22
     4.1   Due Organization; Good Standing and Power......................  22
     4.2   Authorization and Validity of Agreement........................  23
     4.3   No Consents Required; No Conflict with Instruments to which the
           Partnership is a Party.........................................  23

                                      -i-
<PAGE>
 
SECTION 5  COVENANTS SUBSEQUENT TO CLOSING DATE...........................  23
     5.1   Access to Information..........................................  23
     5.2   Mail or Other Communications...................................  24
     5.3   Use of Contributor's Trade Name................................  24
     5.4   Closing Date Balance Sheet.....................................  24
     5.5   Payment of Retained Accounts Payable...........................  24
     5.6   Collection of Accounts Receivable..............................  25
     5.7   Reimbursement for Prepaid Expenses.............................  25
  
SECTION 6  SURVIVAL AND INDEMNIFICATION...................................  25
     6.1   Survival Limitations...........................................  25
     6.2   Indemnification................................................  26
     6.3   Procedures.....................................................  28
     6.4   Subrogation....................................................  30
     6.5   Claims for HSE Work............................................  31
     6.6   EXTENT OF INDEMNIFICATION......................................  31
 
SECTION 7  MISCELLANEOUS..................................................  31
     7.1   Construction...................................................  31
     7.2   Payment of Certain Expenses and Taxes..........................  31
     7.3   Notices........................................................  33
     7.4   [Reserved].....................................................  33
     7.5   Binding Effect; Benefit........................................  33
     7.6   Occasional and Bulk Sales......................................  34
     7.7   Assignability..................................................  34
     7.8   Amendment; Waiver..............................................  34
     7.9   Dispute Resolution.............................................  34
     7.10  Severability...................................................  34
     7.11  Counterparts...................................................  34
     7.12  APPLICABLE LAW.................................................  34
     7.13  JURISDICTION; CONSENT TO SERVICE OF PROCESS; WAIVER............  34
     7.14  WAIVER OF JURY TRIAL...........................................  35
 


                                     -ii-
<PAGE>
 
                  LIST OF SCHEDULES AND EXHIBITS TO AGREEMENT
                  -------------------------------------------


                                   Schedules
                                   ---------

Schedule A            -    Contributed Business
Schedule 2.1(a)       -    Fee Interests, Facilities, Terminals and Warehouses
Schedule 2.1(b)       -    Leases
Schedule 2.1(d)       -    Equipment
Schedule 2.1(k)       -    Contributed Subsidiaries
Schedule 2.2(c)       -    Excluded Tradenames and Logos
Schedule 2.2(h)       -    Certain Excluded Assets
Schedule 2.5(a)(vii)  -    Assumed Indebtedness
Schedule 2.5(a)(x)    -    Assumed Long-Term Liabilities
Schedule 3            -    Disclosure Schedule
 

                                  Appendices
                                  ----------

Appendix A            -    Dispute Resolution Procedures


                                   Exhibits
                                   --------

Exhibit A             -    Form of Deeds for Fee Interests
Exhibit B             -    Form of Assignments of Leases for Leaseholds
Exhibit C             -    Form of Bill of Sale and Assignment  
Exhibit D             -    Form of Trademark Assignment         
Exhibit E             -    Form of Patent Assignment            
Exhibit F             -    Form of Assumption Agreement         
Exhibit G             -    Form of Technology License           
Exhibit H             -    Form of Trademark License            
Exhibit I             -    Form of Intellectual Property License 
 

                                     -iii-
<PAGE>
 
                         ASSET CONTRIBUTION AGREEMENT
                         ----------------------------

     ASSET CONTRIBUTION AGREEMENT (this  "Agreement"), dated as of __________,
199__, between [for Lyondell:  Lyondell Petrochemical Company, a Delaware
corporation] [for Millennium:  Millennium Petrochemicals Inc., a Virginia
corporation] (the "Contributor"), [for Lyondell: Lyondell Petrochemical L.P.
Inc., a Delaware corporation] [for Millennium: Millennium Petrochemicals LP LLC,
a Delaware limited liability company] (the "Contributing Partner") and Equistar
Chemicals, LP, a Delaware limited partnership (the "Partnership").

     WHEREAS,  the Contributor owns all of the issued and outstanding shares of
capital stock of Contributing Partner and the Contributing Partner is a partner
in the Partnership;

     WHEREAS, the Contributor wishes to contribute the assets subject to the
liabilities associated with the olefins, polyolefins and related petrochemicals
businesses described in Schedule A (the "Contributed Business") to the
Contributing Partner; and

     WHEREAS, the Contributing Partner wishes to contribute such assets and
liabilities to the Partnership, and the Partnership wishes to accept such assets
and assume such liabilities, all upon the terms and conditions hereinafter set
forth; and

     WHEREAS, the Partnership will consummate certain transactions and enter
into certain agreements as provided for in the Master Transaction Agreement,
dated as of July 25, 1997, between Lyondell Petrochemical Company and Millennium
Chemicals Inc., as amended (the "Master Transaction Agreement").

     NOW THEREFORE, in consideration of the premises and of the mutual covenants
of the parties hereto, it is hereby agreed as follows:


                                   SECTION 1
                                  DEFINITIONS
                                  -----------
 
     The terms used in this Agreement have the following definitions or are
defined in the Sections referenced below:

     "Accounts Receivable" constitute, as of the Closing Date, all uncollected
accounts receivable that have been generated by, or are attributable to, the
Contributor's operation prior to the Closing Date of the Contributed Business in
the ordinary course and in all respects in a manner consistent with the
provisions of Section 3.2 of the Master Transaction Agreement.
<PAGE>
 
     "Affiliate" means any Person that directly or indirectly through one or
more intermediaries, controls or is controlled by or is under common control
with the Person specified; provided, however, that for purposes of this
Agreement [for Lyondell:  (i) Atlantic Richfield Company and any Person
controlled by it shall not be considered an Affiliate of Contributor;] [for
Millennium:  (i) Suburban Propane Partners, L.P. and any Persons controlled by
it shall not be considered an Affiliate of Contributor;] and (ii) neither the
Partnership nor any Person controlled by it shall be considered an Affiliate of
the Contributor.  For purposes of this definition, the term "control" shall have
the meaning set forth in 17 CFR 230.405 as in effect on the date hereof.

     "Agreed Rate" means the base commercial lending rate announced by Citibank,
N.A. (or its successor) at its principal office in effect from time to time,
such interest rate to change automatically, effective as of the date of each
change in such base rate.

     "Agreement" is defined in the Preamble.

     "Assets" means all of the assets, rights and properties being contributed,
conveyed, assigned, transferred and delivered to the Partnership pursuant to
Section 2.1.

     "Assignment and Assumption Agreements" means the Deeds, the Assignments of
Lease, the Bill of Sale and Assignment, the Trademark Assignment, the Patent
Assignment and the Assumption Agreement.

     "Assignments of Lease" is defined in Section 2.3(a).

     "Associated Rights" is defined in Section 2.1(c).

     "Assumed Liabilities" is defined in Section 2.5(a).

     [For Millennium:  "Assumed Plan" means the Pension Plan for Eligible Hourly
Represented Employees of Quantum Chemical Corporation.]

     "Authority" means any government or governmental or regulatory body
thereof, or political subdivision thereof, whether federal (or any commonwealth,
territory or possession thereof), state, local or foreign, or any agency,
department or instrumentality thereof, or any court or arbitrator (public or
private).

     "Basic Severance" is defined in Section 2.8(b).

     "Capital Spares" means the inventory of spare parts used by the Contributor
in the Contributed Business and owned by the Contributor as of the Closing Date.

     "CERCLA" is defined in Section 3.16(b).

                                      -2-
<PAGE>
 
     "Chemical Substance" means any (i) chemical substance, pollutant,
contaminant, constituent, chemical, mixture, raw material, intermediate, product
or byproduct that is regulated (including any requirement for the reporting of
any Release thereof) under any HSE Law or defined or listed as an industrial,
toxic, deleterious, harmful, radioactive, infectious, disease-causing or
hazardous substance, material or waste under any HSE Law, and (ii) petroleum or
any fraction thereof, asbestos or asbestos-containing material or
polychlorinated biphenyls ("PCBs").

     "Closing" means the closing of the transactions contemplated by the Master
Transaction Agreement.

     "Closing Date" means the date hereof.

     "Closing Date Balance Sheet" is defined in Section 5.4.

     "Code" means the Internal Revenue Code of 1986, as amended.

     [For Millennium:  "Confirmed Accounts Receivable" is defined in Section
5.6.].

     "Consent" means any consent, waiver, appraisal, authorization, exception,
registration, license or declaration of or by any Person or any Authority, or
any expiration or termination of any applicable waiting period under any Legal
Requirement, required with respect to the Contributed Business or the
Contributor or any Affiliate thereof in connection with (i) the execution and
delivery of this Agreement or any of the Related Agreements or (ii) the
consummation of the transactions contemplated hereby or thereby.

     "Contracts" means contracts, maintenance and service agreements, purchase
commitments for materials and other services, advertising and promotional
agreements, leases, taxation agreements with any Authority, and other
agreements.

     "Contributed Contracts" is defined in Section 2.1(f).

     "Contributed Business" is defined in the Preamble.

     "Contributed Intellectual Property" is defined in Section 2.1(g).

     "Contributed Subsidiaries" is defined in Section 2.1(k).

     "Contributor" is defined in the Preamble.

     "Deeds" is defined in Section 2.3(a).

     "De Minimis Claim" means any Third Party Claim for which the Liability
associated therewith is less than $25,000.


                                      -3-
<PAGE>
 
     "Employee Plan" is defined in Section 3.4(a)(i).

     "Encumbrance" means any lien, charge, encumbrance, security interest, title
defect, option or any other restriction or third party right.

     "Environment" is defined in this Section 1 in the definition of "HSE Laws".

     "Equipment" is defined in Section 2.1(d).

     "Excluded Assets" is defined in Section 2.2.

     "Excluded Liabilities" is defined in Section 2.6.

     "Fee Interests" is defined in Section 2.1(a).

     "GAAP" means United States generally accepted accounting principles, as in
effect from time to time.

     "Government Licenses" means all licenses, permits or franchises issued by
any Authority relating to the operation, development, use, maintenance or
occupancy of the Facilities or any other Asset or of the Contributed Business to
extent that such licenses, permits or franchises relate principally to the
normal operation and conduct of the Contributed Business.

     "HSE Claim" means (i) any actions, events, circumstances or
responsibilities (including compliance actions or requirements) that are
necessary to comply with HSE Laws but only to the extent that any of the
foregoing give rise to out of pocket costs or expenses or result in a Liability
that is required by GAAP to be reflected on the balance sheet of the applicable
party or (ii) any third party (including private parties, Authorities and
employees acting on each such party's own behalf or on the behalf of other third
parties) actions, lawsuits, claims, investigations or proceedings arising under
HSE Laws.

     "HSE Laws" means any Legal Requirements or rule of common law now in effect
(including any amendments now in effect) and any current judicial or
administrative interpretation thereof, including any judicial or administrative
order, consent decree, or judgment, relating to (i) any ambient air, surface
water, drinking water, groundwater, land surface, subsurface strata, river
sediment, natural resources or real property and the physical buildings,
structures and fixtures thereon, including sewer, septic and waste treatment,
storage or disposal systems (the "Environment"), including pollution,
contamination, cleanup, preservation, protection and reclamation of the
Environment; (ii) health or safety, including the exposure of employees and
other Persons to any Chemical Substance; (iii) the Release or threatened Release
of any Chemical Substance, noxious noise or odor, including investigation,
study, assessment, testing, monitoring, containment, removal, remediation,
response, cleanup and abatement of such Release or threatened Release; and (iv)
the management of any Chemical Substance, including the manufacture, 

                                      -4-
<PAGE>
 
generation, formulation, processing, labeling, use, treatment, handling,
storage, disposal, transportation, distribution, re-use, recycling or
reclamation of any Chemical Substance.

     "HSE Proceeding" is defined in Section 3.16(d).

     "Indemnified Party" is defined in Section 6.3(a).

     "Indemnifying Party" is defined in Section 6.3(a).

     "Intellectual Property" means research material, technical information,
marketing information, patent rights, patent licenses, pending patent
applications, trade secrets, technical information, know-how, management
information systems, technology, quality control data, specifications, designs,
drawings, software, sales promotion literature and advertising materials.

     "Intellectual Property License" is defined in Section 2.7(b).

     "Inventory" means materials used by the Contributor in the Contributed
Business and owned by the Contributor as of the Closing Date including raw
materials, feed stocks, supplies, additives, pigments, process chemicals,
packaging materials (to the extent the Partnership's use thereof would be
consistent with Section 5.3), catalysts, work-in-process and finished goods that
relate principally to the normal operation and conduct of the Contributed
Business.

     "Inventory Tax" is defined in Section 7.2(d).

     "Knowledge" with respect to the Contributor means the actual knowledge of
(i) any plant manager, (ii) any officer of the Contributor having
responsibilities with respect to the Contributed Business, and (iii) any
employee reporting directly to an officer described in clause (ii), in each case
employed by the Contributor in connection with the Contributed Business.

     "Leased Premises" is defined in Section 2.1(b).

     "Leaseholds" is defined in Section 2.1(b).

     "Leases" is defined in Section 2.1(b).

     "Legal Requirement" means any law, statute, rule, ordinance, decree,
requirement, regulation, order or judgment of any Authority, including the terms
of any Government License.

     "Liability" is defined in Section 6.2(a).

     "Licensed Technology" means the technology licensed to the Partnership
pursuant to the Technology License.

                                      -5-
<PAGE>
 
     "Licensed Trademarks" means the trademarks licensed to the Partnership
pursuant to the Trademark License.

     "Licenses" means the Technology Licenses, Trademark Licenses and
Intellectual Property Licenses.

     "Lowest Cost Response" means the response required or allowed under HSE
Laws that addresses the Chemical Substances present at the lowest cost
(considered as a whole taking into consideration any negative impact such
response may have on the conduct of the Contributed Business and any potential
additional costs or liabilities that may arise as a result of such response) as
compared to any other response that is consistent with HSE Laws.  Taking no
action shall constitute the Lowest Cost Response if, after investigation, taking
no action is determined to be consistent with HSE Laws.  If taking no action is
not consistent with HSE Laws, the least costly non-permanent remedy (such as
mechanisms to contain or stabilize Chemical Substances, including caps, dikes,
encapsulation, leachate collection systems, etc.) shall be the Lowest Cost
Response, provided that such non-permanent remedy is consistent with HSE Laws
and less costly than the least costly permanent remedy (such as the excavation
and removal of soil).

     "Master Transaction Agreement" is defined in the fourth WHEREAS clause.

     "Material Adverse Effect" means any adverse circumstance or consequence
that, individually or in the aggregate, has an effect that is material to the
financial condition, results of operations, assets or business of the
Contributed Business or the Assets, taken as a whole.

     "Neutral" means a neutral Person acceptable to each of the appointing
parties and not affiliated with any of the parties or their Affiliates.

     "Partnership" is defined in the Preamble.

     "Partnership Employees" is defined in Section 2.8(a).

     "Patent Assignment" is defined in Section 2.3(a).

     "PCBs" is defined in this Section in the definition of "Chemical
Substance".

     "Person" means any natural person or any corporation, partnership, limited
liability company, joint venture, association, trust or other entity or
organization.

     "Pre-Closing Contingent Liabilities" means all Liabilities of every kind
and nature arising out of, in connection with or related to the ownership,
operation or use prior to the Closing Date of the Assets or the Contributed
Business other than the Liabilities referred to in Sections 2.5(a)(i), (ii),
(iii),  (vii), (viii) and (ix).


                                      -6-
<PAGE>
 
     "Prepaid Expenses" means the balances in the prepaid accounts consistent
with GAAP of the Contributor or its Affiliates, as of the Closing Date, that are
associated with the Contributed Business and that will have value to the
Partnership in owning and operating the Contributed Business after the Closing
Date.

     "Property Tax" is defined in Section 7.2(c).

     "Related Agreements" means the Master Transaction Agreement, Tier 1 Related
Agreements (other than this Agreement) and Tier 2 Related Agreements of the
Contributor or its Affiliates, as such terms are defined in the Master
Transaction Agreement.

     "Release" means any release, spill, emission, leaking, pumping, injection,
deposit, disposal, dumping, discharge, dispersal, leaching, escaping, emanation
or migration of any Chemical Substance in, into or onto the Environment of any
kind whatsoever, including the movement of any Chemical Substance through or in
the Environment, exposure of any type in any workplace, any release as defined
under the Comprehensive Environmental Response, Compensation and Liability Act
of 1980, as amended, or any other HSE Law and any noxious noise or odor
emission.

     "Retained Accounts Payable" means, as of the Closing Date, all current
trade accounts payable and current accrued expenses other than those related to
[(A)] employee vacation [for Lyondell: and lag-week] accruals for employees that
become Partnership Employees [for Millennium: and (B) the current portion of the
deferred maintenance].

     "SEC Reports" means the 1996 Annual Report on Form 10-K and the 10-Q for
the first quarter of 1997 of the Contributor [for Millennium:'s parent company]
required to be filed with the Securities and Exchange Commission.

     "Seven Year PCCL Claims" means Third Party Claims (other than any De
Minimis Claim) related to Pre-Closing Contingent Liabilities that are asserted
within seven years after the Closing Date.

     "Shared Services Agreements" means the agreements between the Contributor
(or its Affiliates) and the Partnership set forth on Appendix B-2 of the Master
Transaction Agreement.

     "Stores Inventory" means the inventory of spare parts, excluding Capital
Spares, that are used by the Contributor or any Affiliate thereof in the
Contributed Business and owned by the Contributor or any Affiliate thereof as of
the Closing Date  and that consist of items that generally can be used for
several processes or types of equipment, including, but not limited to, such
items as pumps, motors, pipe fittings, electrical wiring, instruments, nuts and
bolts, unfabricated metals, safety items, small hand tools and other
miscellaneous repair parts or supplies.

     "Taxes" means all taxes, charges, fees, levies or other assessments imposed
by any taxing Authority, including, but not limited to, income, gross receipts,
excise, property, sales, use, transfer, 

                                      -7-
<PAGE>
 
payroll, license, ad valorem, value added, withholding, social security,
national insurance (or other similar contributions or payments), franchise,
severance and stamp taxes (including any interest, fines, penalties or additions
attributable to, or imposed on or with respect to, any such taxes, charges,
fees, levies or other assessments).

     "Technology Licenses" is defined in Section 2.7(a).

     "Third Party Claim" means any allegation, claim, civil or criminal action,
proceeding, charge or prosecution brought by a Person other than the
Contributor, any Affiliate thereof, the Partnership, or any member of the [for
Lyondell:  Millennium] [for Millennium:  Lyondell] Group (as defined in the
Master Transaction Agreement).

     "Trademarks" means trade names, trademarks, trademark registrations or
trademark applications, copyrights, copyright applications or copyright
registrations or any derivative thereof or design used in connection therewith.

     "Trademark Assignment" is defined in Section 2.3(a).

     "Trademark License" is defined in Section 2.7(a).

     "Unrecorded Assets:" is defined in Section 2.1(e).

     "WARN" is defined in Section 2.8(f).


                                   SECTION 2
           CONTRIBUTION OF ASSETS; ASSUMPTION OF CERTAIN LIABILITIES
           ---------------------------------------------------------
 
     2.1  Transfer of Assets.  On the terms and subject to the conditions set
forth in this Agreement, on the date hereof, the Contributor contributes to the
Contributing Partner and the Contributing Partner is contributing, conveying,
assigning, transferring and delivering to the Partnership, or shall cause to be
contributed, conveyed, assigned, transferred and delivered to the Partnership,
and the Partnership shall accept, acquire and assume all of the assets, rights,
and properties used or held for use in the contemplated operation and conduct of
the Contributed Business of every kind, nature, character and description,
tangible and intangible, real, personal or mixed, wherever located other than
the Excluded Assets; and which conveyance, subject to Section 2.2, shall
include, without limitation, the following:

     (a)  All right, title and interest of the Contributor and any Affiliate
thereof in the parcels of land described as fee property on Schedule 2.1(a),
together with all buildings, structures, fixtures and other improvements
situated thereon and all right, title and interest of the Contributor and any
Affiliate thereof under easements, privileges, rights-of-way, riparian and other
water rights, lands 

                                      -8-
<PAGE>
 
underlying any adjacent streets or roads, appurtenances and licenses to the
extent pertaining to or accruing to the benefit of the land (the "Fee
Interests");

     (b)  All right, title  and interest of the Contributor and any Affiliate
thereof under the leases and subleases, all amendments thereto and all
agreements related thereto described on Schedule 2.1(b) (the "Leases"), for the
use and occupancy of the premises described therein (the "Leased Premises"),
together with all buildings, structures, fixtures and other improvements
situated thereon and, all rights and interests of the Contributor and any
Affiliate thereof under all easements, privileges, rights-of-way, riparian and
other water rights, appurtenances and licenses pertaining to the Leases or
accruing to the benefit of the tenant under the Leases (the "Leaseholds");

     (c)  All right, title and interest of the Contributor and any Affiliate
thereof, if any, in lands, or real property of others, used principally in the
normal operation and conduct of the Contributed Business (the "Associated
Rights"), including, without limitation, all contracts, easements, rights-of-
way, permits, licenses and leases and other similar rights for related
equipment, power and communications cables, and other related property and
equipment used principally in the normal operation and conduct of the
Contributed Business;

     (d)  All of the right, title and interest of the Contributor and any
Affiliate thereof in and to the equipment, furniture, furnishings, fixtures,
machinery, Capital Spares, vehicles, tools, computers and other tangible
personal property used principally in the  normal operation and conduct of the
Contributed Business including without limitation the items listed on Schedule
2.1(d), (the equipment described in this Section 2.1(d), to be referred to
collectively as the "Equipment") and all warranties and guarantees, if any,
express or implied, existing for the benefit of the Contributor or any Affiliate
thereof in connection with the Equipment to the extent assignable;

     (e)  Subject, to the extent applicable, to Section 5.3, all (i) customer
lists, customer credit information (to the extent neither the Contributor nor
any Affiliate thereof is bound to any confidentiality obligation with respect
thereto), customer payment histories and credit limits, vendor lists, catalogs,
and (ii) Intellectual Property to the extent used or contemplated for use
principally in the normal operation and conduct of  (or to the extent under
development for use principally in the normal operation and conduct of) or the
marketing or promotion of, the Contributed Business (collectively, the
"Unrecorded Assets");

     (f)  All Contracts, whether or not entered into in the ordinary course of
business, that relate principally to the normal operation and conduct of the
Contributed Business, or in the case of any Contracts under which either the
Contributor or any Affiliate thereof  retains rights with respect to its other
businesses, to the extent any such Contract relates to the operation of the
Contributed Business (all the foregoing excluding Government Licenses, but,
together with all agreements and instruments setting forth the Contributor's and
any of its Affiliates' rights with respect to rights-of-way, privileges,
riparian and other rights, appurtenances, licenses or franchises and in respect
of intellectual property rights, in each case that constitute Assets described
in clauses (a) through (e), of this Section 2.1 to be referred to collectively
as the "Contributed Contracts");


                                      -9-
<PAGE>
 
     (g)  Any Trademarks to the extent used or contemplated to be used
principally in the normal operation and conduct of the Contributed Business (all
of the items referred to in this Section 2.1(g), together with the items
referred to in clause (ii) of Section 2.1(e), collectively the "Contributed
Intellectual Property");

     (h)  All Government Licenses that are transferable and as to which Consents
to transfer are obtained where required;

     (i)  The Inventory, Stores Inventory and Prepaid Expenses;

     [(j) For Lyondell: Subject to Section 5.6, Accounts Receivable.]  [For
Millennium: [Reserved]]

     (k)  All right, title and interest of the Contributor and any Affiliate
thereof in the subsidiaries listed on Schedule 2.1(k) (the "Contributed
Subsidiaries");

     (l)  All claims and rights against third parties (including, without
limitation, insurance carriers, indemnitors, suppliers and service providers) to
the extent, but only to the extent that, they relate to the Assumed Liabilities;
provided, however, that to the extent that any claims or rights of the
Contributor against any third parties are not assigned to the Partnership, and
the partnership incurs Liabilities that would create such claims or rights on
behalf of the Contributor, the Contributor shall enforce such claims or rights
for the benefit (and at the cost) of the Partnership to the extent it may
lawfully do so; and

     (m)  Any other asset of the Contributor or its Affiliate contributed to the
Partnership pursuant to the terms of this Agreement.

     2.2  Excluded Assets.  It is expressly understood and agreed that the
Assets shall not include the following (the "Excluded Assets"):

     (a)  Except as otherwise provided in Section 2.1(j), cash and cash
equivalents or similar type investments, such as certificates of deposit,
Treasury bills and other marketable securities;

     (b)  Except [For Millennium: for the Assumed Plan transferred as provided
under Section 2.8(g) or] as may be agreed pursuant to Section 2.8(g), any
assets of any qualified or non-qualified pension or welfare plans or other
deferred compensation arrangements maintained by the Contributor or any
Affiliate thereof for employees of the Contributor or any Affiliate thereof
prior to the Closing Date;

     (c)  Any of the Contributor's or any Affiliate's right, title and interest
in and to (i) the names and logos set forth on Schedule 2.2(c) and any other
statutory names, trade names or trademarks, indications or descriptions of which
such names or any name similar thereto forms a part and (ii) any other trade
names, trademarks, trademark registrations or trademark applications,


                                     -10-
<PAGE>
 
copyrights, copyright applications or copyright registrations or any derivative
thereof or design used in connection therewith that are not used principally in
the normal operation and conduct of and are not uniquely applicable to the
Contributed Business;

     (d)  All claims and rights against third parties (including, without
limitation, insurance carriers, indemnitors, suppliers and service providers),
to the extent they do not relate to the Assumed Liabilities;

     (e)  Claims for refunds of Taxes for time periods ending on or before the
Closing Date, which Taxes remain the liability of Contributor under this
Agreement;

     (f)  Subject to the Technology License and Trademark License, any and all
of the Intellectual Property and Trademarks of the Contributor or any Affiliate
thereof to the extent not used principally in the normal operation and conduct
of or to the extent not applicable to the Contributed Business;

     (g)  All items sold in the ordinary course of business prior to the Closing
Date, none of which individually or in the aggregate are material to the normal
operation and conduct of the Contributed Business; and

     (h)  The tangible assets, intangible assets, real properties, contracts and
rights, described in Schedule 2.2(h).

     2.3  Instruments of Conveyance and Assignment.  On the Closing Date, the
Contributor shall:

     (a)  deliver or cause to be delivered to the Partnership (i) properly
executed and acknowledged warranty deeds, in substantially the form attached
hereto as Exhibit A (the "Deeds"), for all Fee Interests being conveyed
hereunder, (ii) assignments of lease for the Leases in substantially the form
attached hereto as Exhibit B, (the "Assignments of Lease"), (iii) a bill of sale
and assignment in substantially the form attached hereto as Exhibit C (the "Bill
of Sale and Assignment") conveying title to the Assets (other than the Fee
Interests and Leaseholds) and assigning the Contracts, (iv) an assignment of the
trademarks included in the Assets in substantially the form attached hereto as
Exhibit D (the "Trademark Assignment") and (v) an assignment of patent rights,
licenses and applications included in the Assets in substantially the form
attached hereto as Exhibit E (the "Patent Assignment"); and

     (b)  transfer to the Partnership the originals (to the extent the
Contributor or any Affiliate thereof possesses an original and retained no
rights thereunder after the Closing Date) or copies, as appropriate, of the
Contributed Contracts and the originals or copies, as appropriate, of all
current records, files and other data that relate to the Assets and that are
necessary for continuing the normal operation and conduct of the Contributed
Business by the Partnership.

                                     -11-
<PAGE>
 
     2.4  Further Assurances.

     (a)  On and from time to time after the Closing Date, the Contributor will
execute and deliver, or cause to be executed and delivered, such other
instruments of conveyance, assignment, transfer and delivery as the Partnership
may reasonably request in order to fulfill and implement the terms of this
Agreement, to vest in the Partnership title to the Assets, or to enable the
Partnership to realize the benefits intended to be afforded hereby.

     (b)  On and from time to time after the Closing Date, the Partnership will
execute and deliver, or cause to be executed and delivered, such other
instruments of assumption, conveyance, assignment, transfer, power of attorney
or assurance as the Contributor may reasonably request in order to vest in the
Partnership all of the Assumed Liabilities and to enable the Contributor to
realize the benefits intended to be afforded hereby.

     (c)  Notwithstanding any other provision of this Agreement to the contrary,
the Partnership and the Contributor acknowledge and agree that any Government
Licenses, Contributed Contracts or warranties which by their terms require
Consent from any other unaffiliated contracting party thereto shall not be
assigned to the Partnership unless any such Consent has been obtained prior to
the Closing Date.  Following the Closing, the Partnership and the Contributor
shall cooperate with each other and use commercially reasonable efforts to
obtain those Consents that were not obtained prior to the Closing and (i) if
such Consents are obtained following the Closing, the Partnership and the
Contributor shall execute and deliver any other and further instruments of
assignment, assumption, transfer and conveyance and take such other and further
action as the Partnership may request in order to assign to the Partnership any
Government Licenses, Contributed Contracts or warranties to which such Consents
relate and (ii) pending such transfer or issuance to the Partnership, shall
provide, to the extent it may lawfully do so, the Partnership with the benefits
of any such Government Licenses, Contributed Contracts or warranties, in which
case, the Partnership shall promptly assume and discharge (or reimburse the
Contributor or its Affiliate for) all obligations and liabilities associated
with the benefits of such Government Licenses, Contributed Contracts or
warranties so made available to the Partnership.  If the Contributor obtains a
Consent to assign any Government Licenses, Contributed Contract or warranties
after the Closing, each such Government Licenses, Contributed Contract or
warranties shall be deemed to be assigned to the Partnership promptly after such
Consent is obtained.

     (d)  Following the Closing, the Contributor, Contributing Partner and the
Partnership shall cooperate in good faith and in a commercially reasonable
manner with respect to all matters pertinent to the carrying into effect of this
Agreement and the discharge by each party of its obligations and liabilities
hereunder and thereunder, and shall furnish to each other such information,
cooperation and assistance as reasonably may be requested in connection with the
foregoing.


                                     -12-
<PAGE>
 
     2.5  Assumption of Liabilities.

     (a)  On the terms and subject to the conditions, including Section 6.2, set
forth in this Agreement, on the Closing Date, the debts, liabilities and
obligations of the Contributor and its Contributed Subsidiaries set forth in
this Section 2.5 shall be assumed by the Contributing Partner in connection with
the transfer of Assets to it and shall be assumed by the Partnership in
connection with the transfer of Assets to it, and the Partnership agrees to pay,
perform and discharge all such debts, liabilities and obligations when due:

          (i)    All obligations arising after the Closing Date under the
     Contracts and Leases that are assigned to the Partnership hereunder unless
     and to the extent that such obligation arises out of a violation of such
     Contract or Lease prior to the Closing Date;

          (ii)   All obligations under purchase orders accepted by the
     Contributor or its Contributed Subsidiaries in the ordinary course of
     business of the Contributed Business prior to the Closing Date that are not
     filled as of the Closing Date;

          (iii)  Current accrued expenses related to [(A)] employee vacation
     [for Lyondell: and lag-week] accruals for employees that become Partnership
     Employees [for Millennium: and (B) the current portion of the deferred
     maintenance];

          (iv)   All obligations and liabilities, of every kind and nature,
     without limitation, arising out of, in connection with or related to the
     ownership, operation or use after the Closing Date of the Assets or the
     Contributed Business;

          (v)    Seven Year PCCL Claims to the extent the aggregate thereof does
     not exceed $7,000,000;


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

          (vii)  The obligations for indebtedness described on Schedule
     2.5(a)(vii);

          (viii) [For Millennium:  Subject to Section 2.8(g), all Liabilities
     associated with the Assumed Plan] [for Lyondell:  [Reserved]];

          (ix)   All Liabilities associated with products sold after the Closing
     Date regardless of when manufactured;

          (x)    The long-term liabilities set forth on Schedule 2.5(a)(x); and

          (xi)   Any other Liability specifically assumed by the Partnership
     pursuant to the terms of this Agreement.


                                     -13-
<PAGE>
 
The liabilities and obligations assumed by the Partnership pursuant to this
Section are sometimes hereinafter referred to collectively as the "Assumed
Liabilities."

     (b)  On the Closing Date, the Partnership shall deliver to the Contributor
an instrument of assumption of the Assumed Liabilities substantially in the form
attached hereto as Exhibit F (the "Assumption Agreement").

     2.6  Excluded Liabilities.  Except as otherwise expressly provided in this
Agreement (including, without limitation, Sections 6.2 and 7.2) or the
Assumption Agreement, the Partnership is assuming only the Assumed Liabilities
and is not assuming any other liability or obligation of the Contributor or any
Affiliate thereof, of whatever nature, whether presently in existence or arising
hereafter, whether known or unknown, or whether absolute or contingent, and all
such other liabilities and obligations of the Contributor and any Affiliate
thereof that are not Assumed Liabilities shall be retained by and remain
obligations and liabilities of the Contributor or such Affiliate (all such
liabilities and obligations being herein referred to as the "Excluded
Liabilities"), including the following:

          (i)    Any Pre-Closing Contingent Liability that is not an Assumed
     Liability;

          (ii)   any obligation or liability relating to the Excluded Assets;
     and

          (iii)  any obligation (A) for the payment of severance benefits to
     employees of the Contributor or any of its Affiliates except as set forth
     in Sections 2.8(b) or (c), or (B) attributable to Contributor's or any of
     its Affiliates' employment of any employee, agent or independent contractor
     prior to the Closing Date.

     2.7  Technology and Trademark Licenses.

     (a)  Any Intellectual Property and Trademarks used, contemplated for use or
that could be used, in the Contributed Business that is not conveyed to the
Partnership pursuant to Section 2.1 will be licensed at the Closing, to the
Partnership pursuant to non-exclusive, royalty-free licenses ("Technology
Licenses" and "Trademark Licenses") substantially in the forms of Exhibit G and
H hereto.

     (b)  Any Contributed Intellectual Property acquired by the Partnership
pursuant to Section 2.1 of this Agreement used, contemplated for use or that
could be used in the business of the Contributor or its Affiliates will be
licensed at the Closing to the Contributor or its Affiliate pursuant to non-
exclusive, royalty-free licenses (the "Intellectual Property Licenses")
substantially in the form of Exhibit I.

     2.8  Employee Matters.  If the Closing Date occurs prior to January 1,
1998, the effective employment date shall be January 1, 1998 and the Contributor
and the Partnership shall enter into an agreement to provide employee services
to the Partnership through December 31, 1997.


                                     -14-
<PAGE>
 
     (a)  At or prior to the Closing, the Partnership shall determine which
employees of the Contributor or any Affiliate thereof will be offered employment
by the Partnership.  Any such employee that accepts such offer is herein called
a "Partnership Employee."  Partnership Employees shall be employed effective on
(i) January 1, 1998, or (ii) if the Closing Date is after January 1, 1998, the
Closing Date.

     (b)  If, within six months after the Closing Date or in anticipation of
Closing, the Contributor or any Affiliate thereof terminates (other than for
cause) the employment of any employee of the Contributor or any Affiliate
thereof who is primarily associated with the Assets or the Contributed Business
but who does not become a Partnership Employee, then the Partnership will pay to
the Contributor an amount equal to the Basic Severance to the extent the
Contributor or any Affiliate thereof pays the Basic Severance to such employee.
"Basic Severance" means two weeks of base pay for each full year of service by
the employee with the Contributor or any Affiliate (or predecessors of either,
to the extent service therefor is credited by the Contributor), subject to a 52
week maximum and a 12 week minimum; provided, however, that with respect to any
employee who has an employment agreement that contains provisions providing for
one or more payments in the event of a change in control of the Contributor,
"Basic Severance" means up to 52 weeks of base pay notwithstanding the
employee's years of service.

     (c) Any Partnership Employee whose employment is terminated by the
Partnership (other than for cause) within six months after the Closing Date
shall be entitled to receive a severance benefit from the Partnership equal to
the Basic Severance (which, for purposes of calculating service time, shall
include the employee's time of service with the Contributor, its predecessors
(to the extent service therefor is credited by the Contributor) and the
Partnership).

     (d)  Any employees of the Contributor that the Partnership and the
Contributor agree are necessary for the orderly transfer of the Contributed
Business to the Partnership but who will not become Partnership Employees
("Transition Employees") shall be compensated by the Contributor on terms and
conditions and for a duration to be agreed upon by the Partnership and the
Contributor.  The Partnership shall reimburse the Contributor for any such
agreed upon compensation, including payroll taxes, benefit costs  and workers
compensation premiums and claims, paid by the Contributor to or with respect to
any Transition Employee.

     (e)  If any employee of the Contributor is eligible for and receiving short
term disability benefits or sick pay as of the Closing Date and the Partnership
has offered such employee employment by the Partnership, that employee shall
become employed by the Partnership (and become a Partnership Employee for
purposes of this Section 2.8) upon eligibility to return to active employment
with the Contributor under the applicable conditions of the Contributor's short
term disability benefits or sick pay plan.  Partnership employment shall not be
effective until the Contributor verifies that the employee has satisfied the
conditions (if any) to return to active employment.  Until such time as such
employee becomes a Partnership Employee the Contributor shall continue to bear
all costs and expenses associated with such employee.

                                     -15-
<PAGE>
 
     (f)  Neither the Contributor nor any of its Affiliates shall, at any time
prior to 60 days after the Closing Date, effect a "plant closing" or "mass
layoff", as those terms are defined in the Worker Adjustment and Retraining
Notification Act of 1988 ("WARN"), affecting in whole or in part any facility,
site of employment, operating unit or employee of the Contributor or any of its
Affiliates without complying fully with the notice and all other applicable
requirements of WARN.

     (g)  In connection with the development by the Partnership of benefit plans
and programs for Partnership Employees as provided in the Master Transaction
Agreement, (i) the Contributor may direct the trustee of any of its employee
plans to transfer assets and liabilities in those employee plans associated with
the accrued benefits of Partnership Employees to a comparable Partnership
benefit plan in which the Partnership Employees participate, and (ii) the
Contributor or any of its Affiliates may direct the trustee of its grantor trust
to transfer assets and liabilities relating to any accounts for Partnership
Employees under an executive deferral plan to a trust established by the
Partnership to provide benefits under a comparable non-qualified deferred
compensation plan; provided, however, with respect to (i) and (ii) above, the
assets associated with any such plans, as of the Closing Date, are not less than
the liabilities associated therewith as determined by the Partnership and a
trust to trust transfer of assets does not result in a taxable event.  In
connection with the development and implementation of such plans and programs,
the Partnership agrees, for purposes of calculating service time, to include
each employee's time of service with the Contributor, its predecessors (to the
extent service therefor is credited by the Contributor) or the Partnership. [For
Millennium: The Partnership will accept sponsorship of the Assumed Plan as soon
as practicable after the Closing Date and the Contributor shall make all
necessary governmental filings in connection therewith on a timely basis.  In
connection with the transfer of the sponsorship of the Assumed Plan, the
Partnership may require such representations concerning the Assumed Plan as the
Partnership reasonably determines are necessary, including, that the assets are
not less than the liabilities and no Consents from the union are necessary for
such transfer.]

     (h)  To the extent that the Partnership adopts benefit plans or policies
that contemplate the provision of post-retirement life and medical benefits to
the Partnership Employees, the Partnership shall record and recognize, in
accordance with GAAP, the associated liability for providing the post-retirement
life and medical benefits to the Partnership Employees.

     2.9  Joint Contracts.

     (a)  Any Contributed Contracts contributed to the Partnership pursuant to
Section 2.1 that relate principally to the Contributed Business but also relate
to the business (other than the Contributed Business) of the Contributor or its
Affiliates will be made available to the Contributor and its Affiliates by the
Partnership pursuant to the Shared Services Agreements and other arrangements by
which the Contributor and its Affiliates will enjoy the benefits of such
Contributed Contracts as they relate to their business (other than the
Contributed Business) on the same terms and conditions as the Partnership.

                                     -16-
<PAGE>
 
     (b)  Any Contracts that relate principally to the business (other than the
Contributed Business) of the Contributor or its Affiliates but also relate to
the Contributed Business will be made available to the Partnership by the
Contributor or its Affiliates pursuant to the Shared Services Agreements and
other arrangements by which the Partnership will enjoy the benefits of such
Contracts as they relate to the Contributed Business on the same terms and
conditions as the Contributor or its Affiliates.


                                   SECTION 3
               REPRESENTATIONS AND WARRANTIES OF THE CONTRIBUTOR
               -------------------------------------------------
 
     Except as set forth on Schedule 3 or in the SEC Reports, the Contributor
represents and warrants to the Partnership as follows:

     3.1  Due Organization; Good Standing and Power.  The Contributor is a
corporation duly organized, validly existing and in good standing under the laws
of the [for Lyondell: State of Delaware] [for Millennium: Commonwealth of
Virginia] and has the corporate power and authority to own, lease and operate
the properties to be contributed hereunder and to conduct the Contributed
Business as now conducted by it. The Contributor has all corporate power and
authority to enter into this Agreement and the Assignment and Assumption
Agreements and to perform its obligations hereunder and thereunder. The
Contributor is duly authorized, qualified or licensed to do business as a
foreign corporation, and is in good standing, in the State of Texas and in each
of the other jurisdictions in which its right, title or interest in or to any of
the Assets held by it, or the conduct of the Contributed Business by it,
requires such authorization, qualification or licensing, except where the
failure to so qualify or to be in good standing would not reasonably be expected
to have a Material Adverse Effect.

     3.2  Authorization and Validity of Agreements.  The execution, delivery and
performance of this Agreement and the other Related Agreements by the
Contributor and the consummation by it of the transactions contemplated hereby
and thereby have been duly authorized by the Board of Directors of the
Contributor. Except to the extent heretofore obtained, no other corporate or
stockholder action is necessary for the authorization, execution, delivery and
performance by the Contributor of this Agreement and the other Related
Agreements and the consummation by the Contributor of the transactions
contemplated hereby or thereby. This Agreement and the other Related Agreements
have been duly executed and delivered by the Contributor and constitute legal,
valid and binding obligations of the Contributor, enforceable in accordance with
their terms, except as the same may be limited by bankruptcy, insolvency,
reorganization, moratorium and other laws relating to or affecting creditors'
rights generally and by general equity principles.

     3.3  No Consents Required; No Conflict with Instruments to which the
Contributor is a Party.  The execution, delivery and performance of this
Agreement and the other Related Agreements by the Contributor or by any
Affiliate of the Contributor that is a party thereto and the consummation by the
Contributor or any such Affiliate of the transactions contemplated thereby (i)

                                     -17-
<PAGE>
 
will not require any Consent except for such Consents the failure of which to be
obtained or made, would not in the aggregate reasonably be expected to have a
Material Adverse Effect; and (ii) will not violate (with or without the giving
of notice or the lapse of time or both), or conflict with, or result in the
breach or termination of any provision of, or constitute a default under, or
result in the acceleration of the performance of the obligations of the
Contributor or any such Affiliate under, or result in the creation of an
Encumbrance upon any Assets or a portion of the Contributed Business pursuant
to, the charter or by-laws of the Contributor or any such Affiliate, or any
indenture, mortgage, deed of trust, lease, licensing agreement, contract,
instrument or other agreement to which the Contributor or any such Affiliate is
a party or by which the Contributor or any such Affiliate or any of the Assets
held by the Contributor or any such Affiliate is bound, except for such
violations, conflicts, breaches, terminations, defaults, accelerations or
Encumbrances which would not in the aggregate reasonably be expected to have a
Material Adverse Effect.

     3.4  Employee Benefits.

     (a)  (i)    Each of the Contributor's Defined Benefit and Defined
     Contribution Pension Plans covering employees ("Employee Plan") is in
     substantial compliance with applicable requirements prescribed by any and
     all Legal Requirements, including, but not limited to the Code, except for
     violations the occurrence of which would not in the aggregate reasonably be
     expected to have a Material Adverse Effect.  Each Employee Plan that is
     intended to be qualified under Section 401(a) of the Code currently has a
     favorable determination letter from the Internal Revenue Service as to that
     Plan's qualification under Section 401(a) of the Code and nothing has
     occurred since the date of such letter that could reasonably be expected to
     cause the loss of such qualification.

          (ii)   The Contributor has in all material respects performed all
     obligations required to be performed by it under ERISA, the Code and any
     other applicable Legal Requirements and under the terms of each Employee
     Plan, except such failures to perform which would not in the aggregate
     reasonably be expected to have a Material Adverse Effect.  The Contributor
     has received no written notice of the existence of any material default or
     violation by any other party of any of such Legal Requirements, terms or
     requirements applicable to any of the Employee Plans.

          (iii)  Other than routine claims for benefits, the Contributor has not
     received any written notice of any pending material claims or lawsuits
     which have been asserted or instituted against any of the Employee Plans,
     the assets of the trust or funds under the Employee Plans, the sponsor or
     administrator of any of the Employee Plans, or against any fiduciary of any
     of the Employee Plans with respect to the operation of such Plan.

          (iv)   The Contributor has not received any written notice of any
     pending investigation or pending enforcement action by the Pension Benefit
     Guaranty Corporation, the Department of Labor, the Internal Revenue Service
     or any other Authority with respect to any of the Employee Plans.


                                     -18-
<PAGE>
 
          (v)    All contributions required to be made under the terms of the
     Contributor's Employee Plans have been timely made.  No Employee Plan has
     an "accumulated funding deficiency" (within the meaning of section 412 of
     the Code or Section 402 of ERISA).

     (b)  All of the Contributor's "group health plans" (within the meaning of
Code Section 5000(b)(1)) have been operated in substantial compliance with the
group health plan continuation coverage requirements of Section 4980B of the
Code and Sections 601 through 608 of ERISA, Title XXII of the Public Health
Service Act and the provisions of the Social Security Act.

     (c)  There has been no act or omission by the Contributor that has given
rise to or may give rise to material fines, penalties, taxes, or related charges
under Section 502(c), (i) or (l) or Section 4071 of ERISA or Chapter 43 of the
Code or the imposition of a lien pursuant to Sections 401(a)(29) or 412(n) of
the Code or pursuant to ERISA.

     3.5  Title to Assets; Absence of Liens and Encumbrances; Leases.

     (a)  The Contributor has good and marketable title to all of the Fee
Interests described in the Deeds, free and clear of all Encumbrances, except (i)
those exceptions contained in the Deeds, (ii) liens for current taxes not yet
due and payable and mechanics and similar statutory liens arising in the
ordinary course of business, (iii) liens of employees and laborers for current
wages not yet due; (iv) building, zoning and health regulations of the
jurisdictions in which the Assets are located; and (v) such imperfections of
title, easements and Encumbrances, if any, as do not in the aggregate materially
detract from the value or materially interfere with the use of the Assets as
they are currently being used or as otherwise would not reasonably be expected
to have a Material Adverse Effect.

     (b)  The Contributor is the sole lessee under the Leases and the sole party
entitled to the Leasehold interests in favor of the lessee thereunder, and the
sole owner of the improvements situated on the Leased Premises, free and clear
of all Encumbrances affecting the Leaseholds except such Encumbrances, if any,
as do not in the aggregate materially detract from the value or materially
interfere with the use of the Assets or as otherwise would not reasonably be
expected to have a Material Adverse Effect.  Neither Contributor nor any
Affiliate thereof has received from or delivered to the lessors under the
Leaseholds any written notice of termination or threat of termination of the
respective Leaseholds.  True and complete copies of all written lease agreements
(including any written amendments or modifications thereof) constituting, or
evidencing the terms of, the Leaseholds have been delivered to the Partnership.
No material default or event of default on the part of the Contributor nor any
Affiliate thereof under the provisions of any of the Leaseholds, and no event
that with the giving of notice or passage of time or both would constitute such
default or event of default on the part of the Contributor, has occurred (which
default or event of default has not been cured).  Neither the Contributor nor
any Affiliate thereof has received any written notice from any lessor under any
Leasehold, that any material default or event of default on the part of the
Contributor or such Affiliate as lessee under the provisions of any Leaseholds,
or that any event that with the giving of notice or passage of time or both
would constitute such a default or an event of 

                                     -19-
<PAGE>
 
default on the part of the Contributor or any such Affiliate, as lessee, has
occurred (which default or event of default has not been cured). No material
default or event of default on the part of the lessor under the provisions of
any of such Leaseholds, and no event that with the giving of notice or passage
of time or both would constitute such default or event of default on the part of
any such lessor, has occurred (which default or event of default has not been
cured).

     (c)  The Contributor or an Affiliate thereof has good title to all of the
personal property purported to be owned by it, free and clear of all
Encumbrances, except for liens for Taxes not yet due and payable and such
Encumbrances, if any, that do not in the aggregate materially detract from the
value or materially interfere with the use of the Assets (as they are currently
being used) or as otherwise would not reasonably be expected to have a Material
Adverse Effect.

     3.6  Title Matters; Defects in Improvements.  There are no trespassers or
other adverse parties in possession on or affecting the Fee Interests or the
Leased Premises that would reasonably be expected to have a Material Adverse
Effect. Neither the Contributor nor any Affiliate thereof has granted and none
of the foregoing is party to any unrecorded options, rights of refusal, sales
contracts or other such contractual rights in favor of any third parties
relating to the Fee Interests or the Leased Premises. No written notice has been
received by the Contributor or any Affiliate thereof from any insurance company
with respect to the Fee Interests or the Leased Premises or by any board of fire
underwriters claiming any material defects or deficiencies or requiring the
performance of any repairs, replacement, alteration or other work relating to
the improvements situated thereon (in each case, which have not been cured).

     3.7  Working Capital.  The Contributor has operated the Contributed
Business in the ordinary course of business from March 31, 1997 to the Closing
Date such that the Inventory, Stores Inventory, Prepaid Expenses and Accounts
Receivable, as of the Closing Date, are at substantially the same level as would
have existed for the Contributor without regard to the transactions contemplated
by the Master Transaction Agreement.

     3.8  Technology and Similar Rights.  The Contributor owns or is licensed to
use all of the Intellectual Property, Licensed Technology and Licensed
Trademarks, and the Intellectual Property, Licensed Technology and Licensed
Trademarks together constitute all relevant patents, pending patent
applications, invention disclosures, copyrights, software, trade secrets,
technical information, technology, know-how, processes, tradenames, trademarks,
trademark registrations or applications, copyrights, copyright applications or
registrations or any derivative thereof or design used in connection therewith
necessary for the normal operation and conduct of the Contributed Business as it
is currently operated and conducted, except where the failure to have such
ownership or licenses would not reasonably be expected to have a Material
Adverse Effect.

     3.9  Government Licenses, Permits and Related Approvals.  The Government
Licenses constitute all those necessary for the normal operation and conduct of
the Contributed Business as it is currently operated and conducted, except where
the failure to have such Government Licenses would not reasonably be expected to
have a Material Adverse Effect.


                                     -20-
<PAGE>
 
     3.10  All Necessary Assets.  The Assets together with the rights under the
Related Agreements constitute all property and other rights necessary to enable
the Partnership to operate and conduct the Contributed Business in substantially
the same manner as it is being operated and conducted on the date of this
Agreement, except in all cases where the failure of the Partnership to acquire
such property or other rights by conveyance or license would not in the
aggregate reasonably be expected to have a Material Adverse Effect.

     3.11  Conduct of Business in Compliance with Regulatory and Contractual
Requirements.  The Contributor, and any Affiliate thereof, is operating and
conducting the Contributed Business in compliance with all applicable Legal
Requirements, rights of concession, licenses, know-how or other proprietary
rights of others, the failure to comply with which would reasonably be expected
to have a Material Adverse Effect.

     3.12  Legal Proceedings.  There is no litigation, proceeding, claim,
grievance, arbitration, investigation or other action to which the Contributor
or any Affiliate thereof is a party (i) that is pending or, to the Knowledge of
the Contributor, threatened, (ii) that relates in any way to the Assets, to the
operation or conduct of the Contributed Business, or to the transactions
contemplated by this Agreement, and (iii) that upon resolution adverse to
Contributor or any of its Affiliates, could reasonably be expected to have a
Material Adverse Effect.

     3.13  Consents.  Except for the Consents set forth in Schedule [for
Lyondell: 4.2(e)] [for Millennium: 4.3(e)] of the Master Transaction Agreement,
there are no Consents required to be obtained by the Contributor or any of its
Affiliates in connection with the transfer of the Assets or the Contributed
Business to the Partnership except to the extent the failure to obtain such
Consent would not be reasonably likely to have a Material Adverse Effect.

     3.14  Tax Matters.

     (a)   There are no material liens for Taxes (other than for current Taxes
not yet due and payable) upon the Assets.

     (b)   None of the Assets directly or indirectly secures any indebtedness
for money borrowed the interest on which is tax-exempt.

     3.15  [Reserved].

     3.16  HSE Matters.  Except as would not be reasonably likely to have a
Material Adverse Effect:

     (a)   (i)   The Fee Interests, the Leased Premises and the operations of
the Contributor and any Affiliate thereof in connection with the Contributed
Business are in compliance with all HSE Laws and (ii) to the extent arising out
of the Contributor's or any Affiliate's ownership or use of the Assets or
operation of the Contributed Business, there are no Chemical Substances held,


                                     -21-
<PAGE>
 
located, released, generated, treated, stored or disposed of, on, under or from
the Fee Interests or the Leased Premises or in, on or from any fixtures or
improvement thereon in excess of any standard prescribed or permitted by any HSE
Laws or which require corrective or other action pursuant to the provisions of
any HSE Laws.

     (b)  Neither the Contributor nor any Affiliate has received any notice from
any federal, state, or local agency naming the Contributor or such Affiliate as
a potentially responsible party ("PRP"), or otherwise notifying the Contributor
or such Affiliate of any potential liability under either the Comprehensive
Environmental Response, Compensation and Liability Act of 1980, as amended,
("CERCLA" or "Superfund"), the Resource Conservation and Recovery Act of 1976,
as amended ("RCRA"), or any state statute, rule or local regulation imposing
liability similar to CERCLA or RCRA that relates in any way to any Chemical
Substances generated by or derived from the operations on the Fee Interests, or
the Leased Premises; nor has the Contributor nor  any of its Affiliates received
any comparable claim or notice from any private party.

     (c)  The Contributor or an Affiliate thereof, as applicable, has been and
is, in compliance with, all permits, licenses, approvals, permission, or
authorizations necessary for its operations in connection with the Contributed
Business to comply in all respects with HSE Laws.

     (d)  (i)    Neither the Contributor nor any Affiliate thereof has received
written notice of any actual, impending, or potential proceedings, allegations,
claims, losses, actions, investigations or inquiries of any kind in connection
with the Contributed Business and HSE Laws or Chemical Substances ("HSE
Proceedings") and (ii) neither the Contributor nor any Affiliate thereof has any
Knowledge of any facts, events or occurrences that would reasonably be expected
to result in any HSE Proceedings being brought.

     (e)  Neither the Contributor nor any Affiliate thereof is party to, or is
subject to the terms of, any consent order, consent judgment, consent decree,
court or administrative order or judgment, agreement, schedule, or decree issued
by any Authority with respect to the Contributed Business.

     3.17  Investigation to Acquire Knowledge.  Each of the persons covered by
the definition of "Knowledge" set forth in Section 1 has reviewed, with counsel
to the Contributor, the other representations and warranties contained in, and
the Schedules that relate to, this Section 3 to the extent that they relate to
such person's area of responsibility or expertise and has made a reasonable
inquiry as to the accuracy and completeness of such representations, warranties
and Schedules.


                                   SECTION 4
               REPRESENTATIONS AND WARRANTIES OF THE PARTNERSHIP
               -------------------------------------------------
 
     The Partnership represents and warrants to the Contributor as follows:

     4.1  Due Organization; Good Standing and Power.  The Partnership is a
limited partnership duly formed and validly existing under the laws of the State
of Delaware. The

                                     -22-
<PAGE>
 
Partnership has all partnership power and authority to enter into this Agreement
and the other Related Agreements and to perform its obligations hereunder and
thereunder. The Partnership is duly authorized, qualified or licensed to do
business as a foreign partnership, in each of the jurisdictions in which its
right, title or interest in or to any asset, or the conduct of its business,
requires such authorization, qualification or licensing, except where the
failure to so qualify would not have a material adverse effect on the ability of
the Partnership to perform its obligations hereunder or under the Assignment and
Assumption Agreements.

     4.2  Authorization and Validity of Agreement.  The execution, delivery and
performance of this Agreement and the other Related Agreements by the
Partnership and the consummation by the Partnership of the transactions
contemplated hereby and thereby have been duly authorized by all necessary
partnership action on the part of the Partnership. No other partnership action
is necessary for the authorization, execution, delivery and performance by the
Partnership of this Agreement, the other Related Agreements and the consummation
by the Partnership of the transactions contemplated hereby or thereby. This
Agreement and the other Related Agreements have been duly executed and delivered
by the Partnership and constitute legal, valid and binding obligations of the
Partnership, enforceable in accordance with their terms, except as the same may
be limited by bankruptcy, insolvency, reorganization, moratorium and other laws
relating to or affecting creditors' rights generally and by general equity
principles.

     4.3  No Consents Required; No Conflict with Instruments to which the
Partnership is a Party.  The execution, delivery and performance of this
Agreement and the other Related Agreements by the Partnership and the
consummation by it of the transactions contemplated thereby (i) will not require
any Consent except for such Consents the failure of which to be obtained or
made, would not in the aggregate reasonably be expected to have a Material
Adverse Effect on the Partnership's ability to perform its obligations hereunder
or thereunder, and (ii) will not violate (with or without the giving of notice
or the lapse of time or both), conflict with, or result in the breach or
termination of any provision of, or constitute a default under, or result in the
acceleration of the performance of the obligations of the Partnership under, the
partnership agreement of the Partnership, or any indenture, mortgage, deed of
trust, lease, licensing agreement, contract, instrument or other agreement to
which the Partnership is a party or by which the Partnership or any of its
assets or properties is bound, except for such violations, conflicts, breaches,
terminations, defaults, accelerations or liens which would not in the aggregate
reasonably be expected to have a material adverse effect on the Partnership's
ability to perform its obligations hereunder or thereunder.


                                   SECTION 5
                     COVENANTS SUBSEQUENT TO CLOSING DATE
                     ------------------------------------
 
     5.1  Access to Information.  Following the Closing Date, the Partnership
shall afford, and will cause its Affiliates to afford, to the Contributor, its
counsel, accountants and other authorized representatives, during normal
business hours, reasonable access to the books, records and other data of the
Contributed Business with respect to the period prior to the Closing Date (and
any personnel

                                     -23-
<PAGE>
 
familiar therewith) to the extent that such access may be reasonably required by
the Contributor to facilitate (i) the preparation by the Contributor of such tax
returns as it may be required to file with respect to the operations of the
Assets and the Contributed Business or in connection with any audit, amended
return, claim for refund or any proceeding with respect thereto, (ii) the
investigation, litigation and final disposition of any claims which may have
been or may be made against the Contributor in connection with the Assets and
the Contributed Business, (iii) the payment of any amount in connection with any
liabilities or obligations which have not been assumed by the Partnership under
this Agreement and (iv) for any other reasonable business purpose. For a period
of ten years after the date of this Agreement, the Partnership will not dispose
of, alter or destroy any such books, records and other data without giving 90
days' prior notice to the Contributor to permit it, at its expense, to examine,
duplicate or repossess such records, files, documents and correspondence.

     5.2  Mail or Other Communications.  The Contributor authorizes and empowers
the Partnership on and after the Closing Date to receive and open all mail
received by the Partnership relating to the Contributed Business or the Assets
and to deal with the contents of such communications in any proper manner. The
Contributor shall promptly deliver to the Partnership any mail or other
communication received by it on and after the Closing Date pertaining to the
Contributed Business or the Assets and any cash, checks or other instruments of
payment to which the Partnership is entitled. The Partnership shall promptly
deliver to the Contributor any mail or other communication received by it after
the Closing Date pertaining to the Excluded Assets or Excluded Liabilities, and
any cash, checks or other instruments of payment in respect of such.

     5.3  Use of Contributor's Trade Name.  Except as set forth on Schedule
2.2(d), after the Closing Date the Partnership shall be permitted to use any
items of Inventory or packaging material, any sales or promotional materials,
any forms or documents or any other printed material that bear any of the names
[for Lyondell: "Lyondell"] [for Millennium: "Millennium," "USI" or "Quantum"] or
other statutory names, trade names or trademarks, indications or descriptions of
which such names or any name similar thereto forms a part until the earlier to
occur of (i) such time as inventory of such materials existing as of the Closing
Date are used, or (ii) two years after the Closing Date.

     5.4  Closing Date Balance Sheet.  Not later than 60 days after the Closing
Date, the Contributor shall cause [for Lyondell: Coopers & Lybrand L.L.P.] [for
Millennium: Price Waterhouse LLP] to prepare and deliver to the Contributor and
the Partnership an audited balance sheet of the Contributed Business as of the
Closing Date (the "Closing Date Balance Sheet").

     5.5  Payment of Retained Accounts Payable.  The Contributor will retain all
accounts payable including Retained Accounts Payable; however the Partnership,
as payment agent of the Contributor, shall pay such amounts on behalf of the
Contributor on a timely basis. As soon as practicable following the end of each
month after which such Retained Accounts Payable are paid by the Partnership,
but in any event within fifteen days after the end of such month, each
Contributor will reimburse the Partnership for such payments attributable to its
Contributed Business.


                                     -24-
<PAGE>
 
     5.6  Collection of Accounts Receivable.  [For Millennium: The Partnership,
as collecting agent for the Contributor, shall take all commercially reasonable
efforts to collect the Accounts Receivable. As soon as practicable after such
Accounts Receivable are collected, but in any event within fifteen days after
the end of each month, the Partnership shall remit such collections to the
Contributor. If the Accounts Receivable as of the Closing Date as set forth in
the Closing Date Balance Sheet (the "Confirmed Accounts Receivable") are less
than $250 million, then in addition to the foregoing, the Partnership shall pay
the Contributor the difference between $250 million and the Confirmed Accounts
Receivable within 10 days after the receipt of the Closing Date Balance Sheet.
If the Confirmed Accounts Receivable are more than $250 million, the Contributor
shall pay the Partnership the difference between $250 million and the Confirmed
Accounts Receivable.] [For Lyondell: The Partnership shall take all commercially
reasonable efforts to collect the Accounts Receivable; however, to the extent
any Accounts Receivable set forth on the Closing Date Balance Sheet are not
collected within 180 days after the Closing Date by the Partnership, the
Contributor will buy such uncollected Accounts Receivable from the Partnership
at the amount set forth on the Closing Date Balance Sheet.]

     5.7  Reimbursement for Prepaid Expenses.  The Partnership and the
Contributor acknowledge that the Prepaid Expenses attributable to its
Contributed Business have been conveyed to the Partnership solely in order to
facilitate the timely and efficient transfer of the Contributed Business to the
Partnership. Consequently, the Partnership shall reimburse the Contributor for
the Prepaid Expenses associated with its Contributed Business (other than the
prepaid expenses for "turnaround" costs) within 10 days following the receipt of
the Closing Date Balance Sheet.


                                   SECTION 6
                         SURVIVAL AND INDEMNIFICATION
                         ----------------------------
 
     6.1  Survival Limitations.  The representations and warranties of the
parties hereto contained in this Agreement or in any certificate or other
writing delivered pursuant hereto or in connection herewith shall survive the
Closing until the date that is 60 months after the Closing Date, except (i)
Section 3.14, which shall survive until the expiration of the applicable statute
of limitations and (ii) Section 3.5, which shall survive without limitation. No
action can be brought with respect to any breach of any representation or
warranty (except with respect to Section 3.5) pursuant to this Agreement unless
a written notice that complies with Section 6.3 has been delivered pursuant to
such Section 6.3 prior to the expiration of the survival period applicable to
such representation or warranty; provided that upon the giving of such notice,
notwithstanding any other provision of this Agreement the representation and
warranty that is the basis of such action shall continue with respect to such
action beyond the time at which the representation and warranty would otherwise
terminate.


                                     -25-
<PAGE>
 
     6.2  Indemnification.

     (a)  Subject to the other provisions of this Section 6, the Contributor
hereby agrees, to the fullest extent permitted by applicable law, to indemnify,
defend and hold harmless the Partnership and its Affiliates and their respective
officers, directors and employees from, against and in respect of any losses,
claims, damages, fines, penalties, assessments by public agencies, settlement,
cost or expenses (including costs of defense and attorneys' fees) and other
liabilities (any of the foregoing being a "Liability") incurred or suffered by
the Partnership or any of its Affiliates, arising out of, in connection with or
relating to:

          (i)    Any misrepresentation in or breach of the representations and
     warranties of the Contributor or any of its Affiliates in this Agreement,
     the Assignment and Assumption Agreements, the Licenses, or the Master
     Transaction Agreement;

          (ii)   Any failure of the Contributor or any of its Affiliates to
     perform any of its covenants or obligations contained in this Agreement,
     the Assignment and Assumption Agreements, the Licenses, or the Master
     Transaction Agreement;

          (iii)  Excluded Liabilities;

          (iv)  Any Pre-Closing Contingent Liability that is not an Assumed
     Liability; or

          (v)   [for Lyondell: Any action by the Contributor or its Affiliates
     that results in the occurrence of a "Designated Event" as such term is
     defined in the Contributor's or its Affiliates' 1989 Indenture and Medium
     Term Notes described in Schedule 2.5 but only to the extent that the
     Partnership incurs an economic loss directly as a result of the occurrence
     of the "Designated Event" and in such case the Contributor's or its
     Affiliates' indemnification obligation is limited to the amount of such
     economic loss;]

provided, however, that the following limitations shall apply to the
Contributor's indemnification obligations in clauses (i) and (iv) above:

          (A)  the Contributor shall not have any indemnification obligation
     under clause (i) and (iv) above for any individual Liability unless the
     amount of such Liability exceeds $25,000 (the "Individual Basket") (it
     being understood that all Liabilities arising from the same event,
     condition or set of circumstances shall be considered as an individual
     Liability for purposes of such calculation), but if the amount of such
     Liability exceeds the Individual Basket, the entire amount of such
     Liability, including the first $25,000 of such Liability, may be the
     subject of indemnification hereunder; provided, further, that the parties
     agree that the amount of Liability for which indemnification may be sought
     for breach of any representation or warranty under clause (i) above shall
     be calculated taking into account the Individual Basket but without regard
     to any qualification or exception regarding materiality or Material Adverse
     Effect qualification contained in such representation or warranty (it 


                                     -26-
<PAGE>
 
     being understood that such materiality or Material Adverse Effect
     qualifications shall apply for purposes of determining whether there has
     been such a breach in the first place, but once it has been established
     that there is such a breach, the Partnership shall be entitled to indemnity
     relating back to the first dollar); and

          (B)  to the extent any misrepresentation in or breach of the
     representations and warranties of the Contributor results in a Liability of
     the Partnership in excess of the Individual Basket and such Liability would
     also constitute a Pre-Closing Contingent Liability, such misrepresentation
     or breach shall be treated as a Pre-Closing Contingent Liability.

     (b)  NOTWITHSTANDING ANY OTHER PROVISION OF THIS AGREEMENT, TO THE FULLEST
EXTENT PERMITTED BY LAW, NEITHER THE CONTRIBUTOR NOR ANY OF ITS AGENTS,
EMPLOYEES, REPRESENTATIVES OR AFFILIATES SHALL BE LIABLE FOR CONSEQUENTIAL,
INCIDENTAL, INDIRECT OR PUNITIVE DAMAGES IN CONNECTION WITH DIRECT CLAIMS BY THE
PARTNERSHIP (I.E., A CLAIM BY THE PARTNERSHIP THAT DOES NOT SEEK REIMBURSEMENT
FOR A THIRD PARTY CLAIM PAID OR PAYABLE BY THE PARTNERSHIP) WITH RESPECT TO
THEIR INDEMNIFICATION OBLIGATIONS UNDER THIS AGREEMENT UNLESS ANY SUCH CLAIM
ARISES OUT OF THE FRAUDULENT ACTIONS OF THE CONTRIBUTOR.  IN DETERMINING THE
AMOUNT OF ANY LOSS, LIABILITY, OR EXPENSE FOR WHICH THE PARTNERSHIP IS ENTITLED
TO INDEMNIFICATION UNDER THIS AGREEMENT, THE GROSS AMOUNT THEREOF WILL BE
REDUCED (BUT NOT BELOW ZERO) BY THE NET PRESENT VALUE OF ANY CORRELATIVE
INSURANCE PROCEEDS ACTUALLY REALIZED BY THE PARTNERSHIP UNDER POLICIES TO THE
EXTENT THAT THE FUTURE PREMIUM RATE WILL NOT BE INCREASED BY CLAIM EXPERIENCE.

     (c)  Notwithstanding the provisions of Sections 6.2(a)(i) and 6.2(a)(iv),
it is expressly agreed that the Contributor shall not be required to indemnify
the Partnership for any Liability arising out of, in connection with or related
to any HSE Claim to the extent that the condition, event, circumstance or other
basis for the HSE Claim was exacerbated or accelerated by the Partnership.  The
Partnership shall not be deemed to have exacerbated a condition, event,
circumstance or other basis for an HSE Claim by reason of the continuance
thereof after the Closing (i) under circumstances where the Partnership does not
know of its existence and has not breached any legal duty to have conducted an
investigation or inquiry that would have uncovered the matter or (ii) under
circumstances where the Partnership does know of its existence but is taking
commercially reasonable actions to cure the matter or to otherwise achieve
compliance in a commercially reasonable and prudent manner.

     (d)  Subject to the other provisions of this Section 6, the Partnership
hereby indemnifies, to the fullest extent permitted by law, the Contributor and
its Affiliates against and agrees to hold each of them harmless from any and all
Liability incurred or suffered by the Contributor or any of its Affiliates
arising out of or relating to:


                                     -27-
<PAGE>
 
          (i)    Any misrepresentation in or breach of the representations and
     warranties of the Partnership or the failure of the Partnership to perform
     any of its covenants or obligations contained in this Agreement and the
     Assignment and Assumption Agreements or the Licenses;

          (ii)   Assumed Liabilities; or

          (iii)  Any HSE Claim to the extent arising out of the Partnership's
     exacerbation or acceleration of such HSE Claim.

     (e)  NOTWITHSTANDING ANY OTHER PROVISION OF THIS AGREEMENT, TO THE FULLEST
EXTENT PERMITTED BY LAW, NEITHER THE PARTNERSHIP NOR ANY OF ITS AGENTS,
EMPLOYEES, REPRESENTATIVES OR AFFILIATES SHALL BE LIABLE FOR CONSEQUENTIAL,
INCIDENTAL, INDIRECT OR PUNITIVE DAMAGES IN CONNECTION WITH DIRECT CLAIMS BY THE
CONTRIBUTOR WITH RESPECT TO THEIR INDEMNIFICATION OBLIGATIONS UNDER THIS
AGREEMENT UNLESS ANY SUCH CLAIM ARISES OUT OF THE FRAUDULENT ACTIONS OF THE
PARTNERSHIP.  IN DETERMINING THE AMOUNT OF ANY LOSS, LIABILITY, OR EXPENSE FOR
WHICH THE CONTRIBUTOR IS ENTITLED TO INDEMNIFICATION UNDER THIS AGREEMENT, THE
GROSS AMOUNT THEREOF WILL BE REDUCED (BUT NOT BELOW ZERO) BY THE NET PRESENT
VALUE OF ANY CORRELATIVE INSURANCE PROCEEDS ACTUALLY REALIZED BY THE CONTRIBUTOR
UNDER POLICIES TO THE EXTENT THE FUTURE PREMIUM RATE WILL NOT BE INCREASED BY
CLAIM EXPERIENCE.

     (f)  The rights provided to the Partnership pursuant to this Section 6, as
limited by and subject to the provisions of this Section 6, shall be the
Partnership's sole remedy for breach of representation and warranty by or
covenant or obligation of the Contributor under this Agreement,  the Assignment
and Assumption Agreements and the Licenses.  The rights provided to the
Contributor pursuant to this Section 6, as limited by and subject to the
provisions of this Section 6, shall be the Contributor's sole remedy for breach
of representation and warranty by or covenant of obligation of the Partnership
under this Agreement, the Assignment and Assumption Agreements and the Licenses.

     6.3  Procedures.

     (a)  Any Person seeking indemnification under Section 6.2 (the "Indemnified
Party") agrees to give prompt written notice to the party against whom indemnity
is sought (the "Indemnifying Party") of the assertion of any claim that does not
involve a Third Party Claim, which notice shall describe in reasonable detail
the nature of the claim, an estimate of the amount of damages attributable to
such claim to the extent feasible and the basis of the Indemnified Party's
request for indemnification under this Agreement.  If the Indemnifying Party
disputes such claim and such dispute is not resolved by the parties, such
dispute shall be resolved in accordance with Section 7.9.


                                     -28-
<PAGE>
 
     (b)  If an Indemnified Party is notified of a Third Party Claim which may
give rise to a claim for indemnification against any Indemnifying Party under
this Section, then the Indemnified Party shall promptly notify each Indemnifying
Party thereof in writing (including copies of all papers served with respect to
such Third Party Claim), which notice shall describe in reasonable detail the
nature of the Third Party Claim, an estimate of the amount of damages
attributable to the Third Party Claim to the extent feasible and the basis of
the Indemnified Party's request for indemnification under this Agreement;
provided that any failure to timely give such notice shall not relieve the
Indemnifying Party of any of its obligations under this Section 6 except to the
extent that such failure prejudices or impairs, in any material respect, any of
the rights or obligations of the Indemnifying Party.

     (c)  Any Indemnifying Party may, and at the request of the Indemnified
Party shall, participate in and control the defense of the Third Party Claim
with counsel of its choice reasonably satisfactory to the Indemnified Party.
The Indemnified Party shall have the right to employ separate counsel in any
such action and to participate in the defense thereof, but the fees and expenses
of such counsel shall be at the expense of the Indemnified Party unless (i) the
employment thereof has been specifically authorized in writing by the
Indemnifying Party, (ii) the Indemnifying Party failed to assume the defense and
employ counsel or failed to diligently prosecute or settle the Third Party Claim
or (iii) there shall exist or develop a conflict that would ethically prohibit
counsel to the Indemnifying Party from representing the Indemnified Party.  If
requested by the Indemnifying Party, the Indemnified Party agrees to cooperate
with the Indemnifying Party and its counsel in contesting any Third Party Claim
that the Indemnifying Party elects to contest, including, without limitation, by
making any counterclaim against the person or entity asserting the Third Party
Claim or any cross-complaint against any person or entity, in each case only if
and to the extent that any such counterclaim or cross-complaint arises from the
same actions or facts giving rise to the Third Party Claim.  The Indemnifying
Party shall be the sole judge of the acceptability of any compromise or
settlement of any claim, litigation or proceeding in respect of which indemnity
may be sought hereunder, provided that the Indemnifying Party will give the
Indemnified Party reasonable prior written notice of any such proposed
settlement or compromise and will not consent to the entry of any judgment or
enter into any settlement with respect to any Third Party Claim without the
prior written consent of the Indemnified Party, which shall not be unreasonably
withheld.  The Indemnifying Party (if the Indemnified Party is entitled to
indemnification hereunder) shall reimburse the Indemnified Party for its
reasonable out of pocket costs incurred with respect to such cooperation.

     (d)  If the Indemnifying Party fails to assume the defense of a Third Party
Claim within a reasonable period after receipt of written notice pursuant to the
first sentence of subparagraph (c), or if the Indemnifying Party assumes the
defense of the Indemnified Party pursuant to subparagraph (c) but fails
diligently to prosecute or settle the Third Party Claim, then the Indemnified
Party shall have the right to defend, at the sole cost and expense of the
Indemnifying Party (if the Indemnified Party is entitled to indemnification
hereunder), the Third Party Claim by all appropriate proceedings, which
proceedings shall be promptly and vigorously prosecuted by the Indemnified Party
to a final conclusion or settled.  The Indemnified Party shall have full control
of such defense and 

                                     -29-
<PAGE>
 
proceedings; provided that the Indemnified Party shall not settle such Third
Party Claim without the written consent of the Indemnifying Party, which consent
shall not be unreasonably withheld. The Indemnifying Party may participate in,
but not control, any defense or settlement controlled by the Indemnified Party
pursuant to this Section, and the Indemnifying Party shall bear its own costs
and expenses with respect to such participation.

     (e)  Notwithstanding the other provisions of this Section 6.3, if the
Indemnifying Party disputes its potential liability to the Indemnified Party
under this Section 6.3 and if such dispute is resolved in favor of the
Indemnifying Party, the Indemnifying Party shall not be required to bear the
costs and expenses of the Indemnified Party's defense pursuant to this Section
6.3 or of the Indemnifying Party's participation therein at the Indemnified
Party's request, and the Indemnified Party shall reimburse the Indemnifying
Party in full for all costs and expenses of the litigation concerning such
dispute.  If a dispute over potential liability is resolved in favor of the
Indemnified Party, the Indemnifying Party shall reimburse the Indemnified Party
in full for all costs of the litigation concerning such dispute.

     (f)  After it has been determined, by acknowledgment, agreement, or ruling
of court of law, that an Indemnifying Party is liable to the Indemnified Party
under this Section 6, the Indemnifying Party shall pay or cause to be paid to
the Indemnified Party the amount of the Liability  within ten business days of
receipt by the Indemnifying Party of a notice reasonably itemizing the amount of
the Liability but only to the extent actually paid or suffered by the
Indemnified Party.

     (g)  In the event a Third Party Claim is brought in which the liability as
between the Partnership and the Contributor is alleged to be joint (it being
agreed that any Third Party Claim related to a Pre-Closing Contingent Liability
shall be deemed joint) or in which the entitlement to indemnification under this
Section 6 has not been determined, the Partnership and the Contributor shall
cooperate in the joint defense of such Third Party Claim and shall offer to each
other such assistance as may reasonably be requested in order to ensure the
proper and adequate defense of any such matter.  Such joint defense shall be
under the general management and supervision of the party which is expected to
bear the greater share of the liability, unless otherwise agreed; provided,
however, that neither party shall settle or compromise any such joint defense
matter without the consent of the other, which consent shall not be unreasonably
withheld or delayed.  Any uninsured costs of such joint defense shall be borne
as the parties may agree, provided, however, that in the absence of such
agreement, the defense costs shall be borne by the party incurring such costs;
provided, further, that, if it is determined that one party was entitled to
indemnification under this Section 6, the other party shall reimburse the party
entitled to indemnification for all of its costs incurred in connection with
such defense.

     6.4  Subrogation.  In the event of any payment by an Indemnifying Party to
an Indemnified Party in connection with any Liability, the Indemnifying Party
shall be subrogated to and shall stand in the place of the Indemnified Party as
to any events or circumstances in respect of which the Indemnified Party may
have any right or claim against any third party relating to such
                                     
                                     -30-
<PAGE>
 
event or indemnification. The Indemnified Party shall cooperate with the
Indemnifying Party in any reasonable manner in prosecuting any subrogated claim.

     6.5  Claims for HSE Work.  Notwithstanding the other provisions of this
Section 6, in the case of any assertion, claim or demand requiring the
performance of investigatory, removal or remedial work with respect to
(environmental conditions, HSE Laws or Chemical Substances for which the
Partnership may seek indemnification, the Partnership shall have the right to
conduct and control such work provided (i) it uses its good faith, commercially
reasonable efforts to achieve the Lowest Cost Response and (ii) it provides the
Contributor with the opportunity to: (A) review and comment upon any work plans
for any remedial action prior to finalization and implementation; (B) attend
meetings with regulators concerning the remedial action; and (C) have a
representative present during the performance of any remedial action.

     6.6  EXTENT OF INDEMNIFICATION.  WITHOUT LIMITING OR ENLARGING THE SCOPE OF
THE INDEMNIFICATION, RELEASE AND ASSUMPTION OBLIGATIONS SET FORTH HEREIN, TO THE
FULLEST EXTENT PERMITTED BY LAW, AN INDEMNIFIED PARTY SHALL BE ENTITLED TO
INDEMNIFICATION HEREUNDER IN ACCORDANCE WITH THE TERMS HEREOF, REGARDLESS OF
WHETHER THE INDEMNIFIABLE LOSS GIVING RISE TO ANY SUCH INDEMNIFICATION
OBLIGATION IS THE RESULT OF THE SOLE, GROSS, ACTIVE, PASSIVE, CONCURRENT OR
COMPARATIVE NEGLIGENCE, STRICT LIABILITY OR OTHER FAULT OR VIOLATION OF ANY LAW
OF OR BY ANY SUCH INDEMNIFIED PARTY. THE PARTIES AGREE THAT THIS STATEMENT
CONSTITUTES A CONSPICUOUS LEGEND.


                                   SECTION 7
                                 MISCELLANEOUS
                                 -------------
 
     7.1  Construction.  In construing this Agreement, the following principles
shall be followed: (i) no consideration shall be given to the captions of the
articles, sections, subsections or clauses, which are inserted for convenience
in locating the provisions of this Agreement and not as an aid in construction:
(ii) no consideration shall be given to the fact or presumption that any of the
parties had a greater or lesser hand in drafting this Agreement; (iii) examples
shall not be construed to limit, expressly or by implication, the matter they
illustrate; (iv) the word "includes" and its syntactic variants mean "includes,
but is not limited to" and corresponding syntactic variant expressions; (v) the
plural shall be deemed to include the singular, and vice versa; (vi) each gender
shall be deemed to include the other gender; and (vii) each exhibit, appendix,
attachment and schedule to this Agreement is a part of this Agreement.

     7.2  Payment of Certain Expenses and Taxes.

     (a)  Subject to the further provisions of this Section 7.2, the Contributor
shall be responsible for all Taxes attributable to the Contributor's ownership
or use of the Assets or operation of the Contributed Business prior to the
Closing and the Partnership shall be responsible for all 

                                     -31-
<PAGE>
 
Taxes attributable to the Partnership's ownership or use of the Assets or
operation of the Contributed Business after the Closing. The Contributor shall
be responsible for any liability of the Partnership pursuant to Texas Tax Code
Section 111.020 (including interest, penalties and attorneys' fees in connection
therewith) with respect to any amounts owed or owing by the Contributor under
Title 2, Texas Tax Code.

     (b)  All sales, transfer, or other similar taxes incurred in connection
with the transfer of the Assets shall be borne by the Partnership.  The
Partnership, the Contributor and the Contributing Partner shall cooperate fully
with each other after the Closing in connection with (i) the preparation and
filing of any tax return, exemption certificate, or other filing in connection
with such taxes, and (ii) any audit examination by any taxing Authority of the
tax returns, exemption certificates, or other filings referred to above.

     (c)  All real property taxes, personal property taxes, ad valorem taxes,
and other similar taxes (or payments in lieu of such taxes) assessed on any of
the Assets in the tax period in which the Closing Date occurs (other than the
Inventory Taxes referred to in Section 7.2(d) below) ("Property Taxes") shall be
prorated between the Partnership and the Contributor as of the Closing.

     (d)  All real property taxes, personal property taxes, ad valorem taxes,
and other similar taxes (or payments in lieu of such taxes) assessed on the
Inventory or Stores Inventory in the tax period in which the Closing Date occurs
("Inventory Tax") shall be payable by the Contributor.

     (e)  The Partnership shall pay any title or recordation fees in connection
with the transfer of the Assets.  The Partnership shall also pay for any title
insurance policies or surveys of the Fee Interests that are requested or ordered
by the Partnership.

     (f)  After the Closing, the Contributor receiving each Property Tax or
Inventory Tax bill or notice applicable to the Assets for the period in which
the Closing Date occurred shall promptly notify the Partnership and shall pay
each such tax bill prior to the last day such taxes may be paid without penalty
or interest.  The Partnership shall promptly on receipt of a written request
(accompanied by appropriate supporting documentation) reimburse the paying party
with respect to the Partnership's share of such amount so paid as provided under
this Agreement.  The Contributor and the Partnership shall cooperate fully with
each other on and after Closing with respect to any Property Tax assessment or
valuation (or protest in connection therewith) by any taxing Authority with
respect to the tax period in which the Closing Date occurs.

     (g)  If either party receives a refund of any Taxes for which the other is
liable or responsible under this Agreement, the party receiving such refund
shall, within 30 days after the receipt of such refund, remit it to the party
who is liable.

     (h)  Notwithstanding any other provision of this Agreement, the obligations
of the parties set forth in this Section 7.2 shall be unconditional and absolute
and shall remain in effect until audit, assessment and collection of any such
taxes are barred by the applicable statute of limitations.

                                     -32-
<PAGE>
 
     7.3  Notices.  All notices, requests, demands and other communications
which are required or may be given under this Agreement shall unless otherwise
provided for elsewhere in this Agreement, be in writing and shall be deemed to
have been duly given if and when (i) transmitted by telecopier facsimile with
proof of confirmation from the transmitting machine, or (ii) delivered by
courier or other hand delivery, as follows:

     (a)  If to the Contributor:

          _____________________
          _____________________
          _____________________
          _____________________
          _____________________

     (b)  If to the Contributing Partner:

          _____________________
          _____________________
          _____________________
          _____________________
          _____________________

     (c)  If to the Partnership:

          _____________________
          _____________________
          _____________________
          _____________________
          _____________________

or to such other address or telecopy number as either party shall have specified
by notice in writing to the other party.  All such notices, requests, demands
and communications shall be deemed to be effective upon receipt.

     7.4  [Reserved].

     7.5  Binding Effect; Benefit.  Subject to Section 7.7, this Agreement shall
inure to the benefit of and be binding upon the parties hereto and their
respective permitted successors and assigns. Nothing in this Agreement,
expressed or implied, is intended to confer on any Person other than the parties
hereto or their respective permitted successors and assigns, any rights,
remedies, obligations or liabilities under or by reason of this Agreement.

                                     -33-
<PAGE>
 
     7.6  Occasional and Bulk Sales.  To the extent applicable, the Partnership
and the Contributor each agree to waive, to the fullest extent permitted by law,
compliance by the other with the provisions of the Bulk Sales Law of any
jurisdiction.

     7.7  Assignability.  Neither this Agreement nor any of the rights or
obligations hereunder shall be assignable (by operation of law or otherwise) by
the Contributor or the Contributing Partner without the prior written consent of
the Partnership or shall be assignable (by operation of law or otherwise) by the
Partnership (except to a wholly-owned subsidiary thereof) without the prior
written consent of the Contributor. Any assignment or purported assignment in
violation of this Section shall be null and void.

     7.8  Amendment; Waiver.  This Agreement may be amended, supplemented or
otherwise modified only by a written instrument executed by the parties hereto.
No waiver by any party of any of the provisions hereof shall be effective unless
explicitly set forth in writing and executed by the party so waiving. Subject to
the agreements and obligations of the Partnership hereunder or under applicable
Legal Requirements, no investigations by the Partnership heretofore or hereafter
made shall affect the representations and warranties of the Contributor, and,
except as otherwise provided in Section 6.1, such representations and warranties
shall survive any such investigation. The waiver by any party hereto of a breach
of any provision of this Agreement shall not operate or be construed as a waiver
of any subsequent breach.

     7.9  Dispute Resolution.  All disputes under this Agreement shall be
resolved in accordance with the Dispute Resolution Procedures set forth in
Appendix A.

     7.10  Severability.  In the event that any provisions of this Agreement
shall finally be determined to be unlawful, such provision shall, so long as the
economic and legal substance of the transactions contemplated hereby is not
affected in any materially adverse manner as to Contributor, the Contributing
Partner or the Partnership, be deemed severed from this Agreement and every
other provision of this Agreement shall remain in full force and effect.

     7.11  Counterparts.  This Agreement may be executed in any number of
counterparts, each of which shall be deemed to be an original and all of which
together shall be deemed to be one and the same instrument.

     7.12  APPLICABLE LAW.  THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED
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 SUBJECT TO THE LAWS OF ANOTHER JURISDICTION PURSUANT TO THE LAWS OF
SUCH OTHER JURISDICTION.

     7.13  JURISDICTION; CONSENT TO SERVICE OF PROCESS; WAIVER.  ANY JUDICIAL
PROCEEDING BROUGHT AGAINST ANY PARTY TO THIS AGREEMENT OR ANY DISPUTE UNDER OR
ARISING OUT OF OR IN CONNECTION WITH THIS 


                                     -34-
<PAGE>
 
AGREEMENT OR ANY MATTER RELATED HERETO SHALL BE BROUGHT IN THE FEDERAL OR STATE
COURTS OF THE STATE OF DELAWARE, AND, BY EXECUTION AND DELIVERY OF THIS
AGREEMENT, EACH OF THE PARTIES TO THIS AGREEMENT ACCEPTS THE EXCLUSIVE
JURISDICTION OF SUCH COURTS AND IRREVOCABLY AGREES TO BE BOUND BY ANY JUDGMENT
(AS FINALLY ADJUDICATED) RENDERED THEREBY IN CONNECTION WITH THIS AGREEMENT
EXCEPT TO THE EXTENT THIS AGREEMENT RELATES TO THE CONVEYANCE OR ASSIGNMENT OF
ANY INTEREST IN REAL ESTATE OR THE CREATION, PERFECTION, PRIORITY OR FORECLOSURE
OF ANY LIEN ON ANY INTEREST IN REAL ESTATE IN WHICH CASE, SUCH COURTS
JURISDICTION SHALL BE NON-EXCLUSIVE. EACH OF THE PARTIES TO THIS AGREEMENT SHALL
APPOINT THE CORPORATION TRUST COMPANY, THE PRENTICE-HALL CORPORATION SYSTEM,
INC. OR A SIMILAR ENTITY (THE "AGENT") AS AGENT TO RECEIVE ON ITS BEHALF SERVICE
OF PROCESS IN ANY PROCEEDING IN ANY SUCH COURT IN THE STATE OF DELAWARE BY
ENTERING INTO AN AGREEMENT AS OF THE DATE OF THIS AGREEMENT WITH THE AGENT TO
SUCH EFFECT. THE FOREGOING CONSENTS TO JURISDICTION AND APPOINTMENTS OF AGENT TO
RECEIVE SERVICE OF PROCESS SHALL NOT CONSTITUTE GENERAL CONSENTS TO SERVICE OF
PROCESS IN THE STATE OF DELAWARE FOR ANY PURPOSE EXCEPT AS PROVIDED ABOVE AND
SHALL NOT BE DEEMED TO CONFER RIGHTS ON ANY PERSON OTHER THAN THE PARTIES
HERETO. EACH PARTY HEREBY WAIVES ANY OBJECTION IT MAY HAVE BASED UPON LACK OF
PERSONAL JURISDICTION, IMPROPER VENUE OR FORUM NON CONVENIENS.

     7.14  WAIVER OF JURY TRIAL.  THE PARTNERSHIP, THE CONTRIBUTING PARTNER AND
THE CONTRIBUTOR HEREBY KNOWINGLY AND INTENTIONALLY, IRREVOCABLY AND
UNCONDITIONALLY WAIVE TRIAL BY JURY IN ANY LEGAL ACTION OR PROCEEDING RELATING
TO THIS AGREEMENT AND FOR ANY COUNTERCLAIM THEREIN.


                                     -35-
<PAGE>
 
     IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement as of the date first above written.



                              [CONTRIBUTOR]



                              By:______________________________
                              Name:
                              Title:



                              [CONTRIBUTING PARTNER]



                              By:______________________________
                              Name:
                              Title:



                              [PARTNERSHIP]



                              By:______________________________
                              Name:
                              Title:




                                     -36-
<PAGE>
 
                                  SCHEDULE A
                                  ----------


For Lyondell:

          The businesses described in the PETROCHEMICALS SEGMENT Section of
Lyondell Petrochemical Company's 1996 Annual Report on Form 10-K except the
assets and operations related to Lyondell Methanol described therein.


For Millennium:

          The businesses described in the Millennium Petrochemicals section of
Millennium Chemicals Inc.'s 1996 Annual Report on Form 10-K under the
subheadings:  (i) Polyethylene and Related Products, (ii) Acetyls and Ethyl
Alcohol (other than the business described in the Acetic Acid and VAM and
Methanol subsections thereof), and (iii) Performance Polymers.
<PAGE>
 
                                Schedule 2.1(a)

                     Facilities, Terminals and Warehouses
                     ------------------------------------

                           To Be Attached At Closing

[Including, with respect to Millennium: Millennium's Research Center located in
Cincinnati, Ohio]
<PAGE>
 
                                Schedule 2.1(b)

                           To be attached at Closing

                           



                                     -39-
<PAGE>
 
                                Schedule 2.1(d)

                           To be attached at Closing




                                      -40
<PAGE>
 
                                Schedule 2.1(k)

                           Contributed Subsidiaries
                           ------------------------

[For Lyondell:

     (i)  Lyondell Mont Belvieu Corporation

     (ii) Lyondell Transportation Company]

[For Millennium:  Quantum Pipeline Company]



                                     -41-
<PAGE>
 
                                Schedule 2.2(h)

                            Certain Excluded Assets
                            -----------------------

[With respect to Lyondell:  (i) Lyondell's interest in and assets associated
with the methanol business of Lyondell Methanol Company L.P. and the related
hydrogen purification and sales; (ii) certain technology rights (ARCO Technology
Licensing & Immunity From Suit Agreements & prod flex technology (including
Lyondell improvements))*; (iii) mainframe leases (computers & equipment) to be
transferred to Lyondell-CITGO Refining Company Ltd. ("LCR"); (iv) mainframe
owned assets (hardware & software) to be transferred to LCR; (v) assets
associated with Lyondell's ongoing corporate operations, including equipment,
records, computer hardware and software and other personal property and
fixtures; (vi) Outstanding claims related to Mt. Belvieu valve failure in 1996
and Colonial Pipeline fire in 1995; (vii) Lyondell's interest in the following
subsidiaries: Lyondell Refining Company, Lyondell General Methanol Company,
Lyondell Limited Methanol Company and  Lyondell FSC, Inc.; and (viii) the assets
of Lyondell (or its Affiliates) that are covered by a Shared Services Agreement
in which the service is to be provided by Lyondell or its Affiliates to the
Partnership.]

*To be licensed to the Partnership pursuant to Technology License.

[With respect to Millennium: (i) Millennium's corporate office and data center
located in Cincinnati, Ohio and all equipment, personal property and fixtures
associated therewith; (ii) the cafeteria/conference center adjacent to
Millennium's office and data center in Cincinnati, Ohio and all equipment,
personal property and fixtures associated therewith; (iii) assets associated
with the ongoing corporate operations of Millennium Petrochemicals and its
direct and indirect corporate parents, including equipment, records, computer
hardware and software and other personal property and fixtures; (iv) assets
associated with the businesses described under the headings "Millennium
Petrochemicals--Acetyls and Ethyl Alcohol--Acetic Acid and VAM" and "--Methanol"
in its 1996 Annual Report on Form 10-K, as such businesses are being conducted
on the date of this Agreement (the "Acetyls Business") and located within the
boundaries of the Acetic Acid, VAM and Methanol (including Syngas) production
facilities at Millennium Petrochemicals' LaPorte, Texas facility, as such
boundaries are established by agreement between Millennium Petrochemicals Inc.
and Lyondell Petrochemical Company before the Closing Date (the "Boundaries");
including without limitation the waste water treatment plant and the barge dock
at Millennium Petrochemicals' LaPorte, Texas facility and associated equipment;
(v) assets used or held for use in the operation and conduct of the Acetyls
Business as such businesses are being conducted on the date of this Agreement
and not either (y) located within the Boundaries or (z) provided to Millennium
Petrochemicals under a Shared Services Agreement; (vi) outstanding claims
related to Millennium Petrochemicals v. M.W. Kellogg Co., (vii) all subsidiaries
of Millennium Petrochemicals other than Quantum Pipeline Company, including
without limitation CUE Insurance Limited, DR Insurance Company, Millennium
Plastics Inc., Millennium Polymers Inc., Millennium Chemicals Export Ltd.,
Millennium Petrochemicals Canada, Ltd., NDCC International II Inc., USI
Chemicals International,
<PAGE>
 
Inc., Quantum UK Limited, Millennium Petrochemicals Europe B.V., and Suburban
Propane GP, Inc.; (viii) Millennium Petrochemical's interest in Suburban Propane
Partners, L.P. and any entities controlled by it; (ix) Millennium
Petrochemical's former research laboratories on Section Road, Cincinnati, Ohio,
(x) certain unimproved real estate at Millennium Petrochemicals' LaPorte, Texas
Facility proximate to the real estate retained by Millennium Petrochemicals
under (iv) above, ** (xi) Accounts Receivable of the Contributor as of the
Closing Date, (xii) the assets of Millennium (or its Affiliates) that are
covered by a Shared Service Agreement in which the service is to be provided by
Millennium (or its Affiliates) to the Partnership [Query whether Amoco's PAO
facility at LaPorte is on land owned by Amoco or on land owned by Millennium, in
which case it should be excluded].]

**   The open or unimproved real estate at LaPorte, Texas to be retained by
     Millennium Petrochemicals will be selected on the principle that the
     Partnership and Millennium Petrochemicals shall both have room for
     expansion at LaPorte.  Final selection of the excluded land shall be made
     before execution of the definitive Asset Contribution Agreement.


                                     -43-
<PAGE>
 
                                Schedule 2.2(c)

              Excluded names, logos, tradenames, trademarks, etc.
              ---------------------------------------------------

[For Lyondell:

(i)  all marks with "Lyondell", including Lyondell.com and all rights to "LYO"

(ii) Synergist Logo;


[For Millennium:  The Millennium Chemicals, Millennium Petrochemicals, Quantum
Chemicals, Quantum Petrochemicals, USI, National Distillers and Chemical
Corporation trademarks and trade names]

                                     -44-
<PAGE>
 
                             Schedule 2.5(a)(vii)

                             Assumed Indebtedness
                             --------------------

[For Lyondell:
 
PUBLIC DEBT
-----------
 
1989 Indenture     $150,000,000        Due June 1999    
                                                        
1992 Indenture     $100,000,000        Due March 2002   
                                                        
1996 Indenture     $150,000,000        Due February 2006 
                   $150,000,000        Due February 2026
 

MEDIUM TERM NOTES
-----------------

$195,000,000       Due Jan. 1998-March 2005]


[For Millennium:  The Millennium Debt as defined in the Master Transaction
Agreement]



                                     -45-
<PAGE>
 
                              Schedule 2.5(a)(x)

                             Long-term Liabilities
                             ---------------------

The following liabilities related to (i) the operations of the Contributed
Business or (ii) employees who will become employees of the Partnership:

          Deferred Compensation
          Other post-retirement benefits
          Deferred licensing revenue
          Environmental reserves
          Other deferred credits
          [For Millennium: Long-term portion of deferred maintenance]



                                     -46-
<PAGE>
 
                                  Schedule 3

                              Disclosure Schedule
                              -------------------

[For Lyondell: None]

[For Millennium: None]




                                     -47-
<PAGE>
 
                                  Appendix A

                         Dispute Resolution Procedures
                         -----------------------------


     (1)  Binding and Exclusive Means.  The dispute resolution provisions set
forth in this Appendix A shall be the binding and exclusive means to resolve all
disputes arising under this Agreement (each a "Dispute").

     (2)  Standards and Criteria.  In resolving any Dispute, the standards and
criteria for resolving such dispute shall, unless the Contributor and the
Partnership in their discretion jointly stipulate otherwise, be as set forth in
Appendix 1 to this Appendix A.

     (3)  ADR and Binding Arbitration Procedures.  If a Dispute arises, the
following procedures shall be implemented:

     (a)  The Indemnifying Party may at any time invoke the dispute resolution
procedures set forth in this Appendix A as to any Dispute by providing written
notice of such action to the Indemnified Party, who within five Business Days
after such notice shall schedule a meeting to be held in Houston, Texas between
the parties.  The meeting shall occur within 10 Business Days after notice of
the meeting is delivered to the Indemnifying Party.  The meeting shall be
attended by representatives of each party having decision-making authority
regarding the Dispute as well as the dispute resolution process and who shall
attempt in a commercially reasonable manner to negotiate a resolution of the
Dispute.

     (b)  The representatives of the parties shall cooperate in a commercially
reasonable manner and shall explore whether techniques such as mediation,
minitrials, mock trials or other techniques of alternative dispute resolution
might be useful.  In the event that a technique of alternative dispute
resolution is so agreed upon, a specific timetable and completion date for its
implementation shall also be agreed upon.  The representatives will continue to
meet and discuss settlement until the date (the "Interim Decision Date") that is
the earliest to occur of the following events: (i) an agreement shall be reached
by the parties resolving the Dispute; (ii) one of the parties shall determine
and notify the other party in writing that no agreement resolving the Dispute is
likely to be reached; (iii) if a technique of alternative dispute resolution is
agreed upon, the completion date therefor shall occur without the parties having
resolved the Dispute; or (iv) if another technique of alternative dispute
resolution is not agreed upon, two full meeting days (or such other time period
as may be agreed upon) shall expire without the parties having resolved the
Dispute.

     (c)  If, as of the Interim Decision Date, the parties have not succeeded in
negotiating a resolution of the dispute pursuant to subsection (b), the parties
shall proceed under subsection (d).

     (d)  The parties shall jointly appoint a Neutral.  If the parties have been
unable to agree upon such appointment within 30 days after the Interim Decision
Date, then such Neutral, upon the 
<PAGE>
 
application of either of the parties shall be appointed within 10 days of the
filing of such application by the Center for Public Resources, or if such
appointment is not so made promptly then promptly thereafter by the American
Arbitration Association in Philadelphia, Pennsylvania, or if such appointment is
not so made promptly then promptly thereafter by the senior United States
District Court judge sitting in Wilmington, Delaware. The fees of the Neutral
shall be paid equally by the parties except that the Neutral shall have
discretion to award fees.

     (e) In consultation with the Neutral, the parties shall agree upon a
binding schedule and procedure (which procedure may have been previously
discussed under subsection (b)) to be used as a means to resolve or to attempt
to resolve Dispute, with the Neutral making the decision as to the schedule
and/or procedure if the parties have been unable to agree on any of such matters
within 20 days after the initial selection of the Neutral.  The parties agree to
participate in a commercially reasonable manner in the procedure to its
conclusion as determined by the Neutral.  If the parties are not successful in
resolving the Dispute through the procedure described above, then the parties
agree that (i) the Neutral shall act as the arbitrator in a binding arbitration
in accordance with the American Arbitration Association rules and shall render a
decision and (ii) judgment upon the decision rendered by the Neutral may be
entered in any court having jurisdiction.

     (4)  Continuation of Business. Notwithstanding the existence of any Dispute
or the pendency of any procedures pursuant to this Appendix A, the parties agree
and undertake that all payments not in dispute shall continue to be made and all
obligations not in dispute shall continue to be performed.



                                      -2-
<PAGE>
 
                                  Appendix 1
                                  ----------

     (a)  First priority shall be given to maximizing the consistency of the
resolution of the Dispute with the satisfaction of all express obligations of
the parties and their Affiliates as set forth in the Agreement.

     (b)  Second priority shall be given to resolution of the Dispute in a
manner which best achieves the objectives of the business activities and
arrangements under the Agreement and permits the parties to realize the benefits
intended to be afforded thereby.

     (c)  Third priority shall be given to such other matters, if any, as the
parties or the Neutral shall determine to be appropriate under the
circumstances.


                                      -3-
<PAGE>
 
                                   Exhibit A

                           To be attached at Closing



                                      -4-
<PAGE>
 
                                   Exhibit B

                           To be attached at Closing

                           


                                      -5-
<PAGE>
 
                                   Exhibit C

                           To be attached at Closing


                                      -6-
<PAGE>
 
                                   Exhibit D

                           To be attached at Closing


                                      -7-
<PAGE>
 
                                   Exhibit E

                           To be attached at Closing



                                      -8-
<PAGE>
 
                                   Exhibit F

                           To be attached at Closing



                                      -9-
<PAGE>
 
                                   Exhibit G

                         Terms of Technology Licenses
                         ----------------------------
                       (from Contributor to Partnership)

(i)    Perpetual and irrevocable

(ii)   Non-exclusive

(iii)  Royalty-free

(iv)   Grant back of Partnership improvements[; provided, however, that any
       significant improvement would not be granted back but instead a right of
       first refusal would be granted.]

(v)    Partnership - No rights to sublicense



             [Actual Form of Agreement to be Attached at Closing]


                                     -10-
<PAGE>
 
                                   Exhibit H

                          Terms of Trademark Licenses
                          ---------------------------
                       (from Contributor to Partnership)


(i)    Non-exclusive

(ii)   Royalty-free

(iii)  No rights to sublicense

(iv)   Right of control in Licensor


             [Actual Form of Agreement to be Attached at Closing]


                                     -11-
<PAGE>
 
                                   Exhibit I

                    Terms of Intellectual Property License
                    --------------------------------------
                      (from Partnership to Contributors)


(i)    Perpetual and irrevocable (except for Trademarks)

(ii)   Non-exclusive

(iii)  Royalty-free

(iv)   Grant backs of improvements[; provided, however, that any significant
       improvement would not be granted back but instead a right of first
       refusal would be granted.]

(v)    Contributors - no rights to sublicense


             [Actual Form of Agreement to be Attached at Closing]

                                     -12-