<PAGE>
                                                                   EXHIBIT 10.16

 
              "Pages where confidential treatment has been requested are stamped
                Confidential Treatment Requested. The redacted material has been
             marked at the appropriate place and in the margin with a star (*)."

                    CCC PRODUCT SALE AND PURCHASE AGREEMENT
                    ---------------------------------------

     THIS  PRODUCT SALE AND PURCHASE AGREEMENT (the "Agreement") is made and
entered into effective as of the 1st day of September, 1996, by and between
WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP, a Delaware limited partnership
with offices at 13430 Northwest Freeway, Suite 1200, Houston, TX  77040-6095
(hereinafter referred to as "WPC"), and CHEVRON CHEMICAL COMPANY,  a Delaware
corporation with offices at 1301 McKinney Street, Houston, TX 77010 (hereinafter
referred to as "CCC").

                                 WITNESSETH:

     WHEREAS, Chevron U.S.A. Inc. ("CUSA"), and NGC Corporation ("NGC"), have
entered into certain agreements ( the "Merger Agreements") pursuant to which
CUSA would contribute certain gas gathering, processing and other midstream
assets and related liabilities of CUSA's Warren Petroleum Company division
("Warren") and natural gas business unit division to a corporation to be formed
which NGC would then be merged into (the "Merger");

     WHEREAS, immediately subsequent to the Merger, the gas gathering,
processing and other midstream assets and related liabilities of Warren will be
transferred to WPC;

     WHEREAS, Warren previously sold to CCC and CCC purchased from Warren all of
CCC's Product and, from time to time, Offspec Product needs and both CCC and WPC
desire that such relationship continue; and

     WHEREAS, WPC has quantities of Products (as defined in Article I below)
available for sale from certain of its facilities located in Mont Belvieu,
Texas, that it desires to sell to CCC, and CCC desires to purchase such Products
from WPC.

     NOW, THEREFORE, in consideration of the premises and for the mutual benefit
of the parties as well as for other good and valuable consideration, WPC and CCC
agree as follows:

                                   ARTICLE I
                                  DEFINITIONS
                                  -----------

     1.1  As used in this Agreement, the following terms shall be given the
following meanings:

     Additional Volumes shall have the meaning specified in Section 6.1
     hereinafter.

     Affiliate shall mean any Person that directly or indirectly through one or
     more intermediaries, controls or is controlled by or is under common
     control with the Person 

                                       1
<PAGE>
 
     specified. The term "control" (including the terms "controlled by" or
     "under common control with") means the possession, directly or indirectly,
     of the power to direct or cause the direction of the management and
     policies of a Person, whether through ownership, by contract, or otherwise.
     Any Person shall be deemed to be an Affiliate of any specified Person if
     such Person owns 50% or more of the voting securities of the specified
     Person, if the specified Person owns 50% or more of the voting securities
     of such Person, or if 50% or more of the voting securities of the specified
     Person and such Person are under common control.

     Alternate Index shall have the meaning specified in Section 5.2
     hereinafter.

     Arbitration Notice shall have the meaning specified in Section 15.1(d)
     hereinafter.

     Bankruptcy Event shall mean the occurrence of one or more of the following
     events with respect to a Party: (A) the entry of a decree or order for
     relief against a Party by a court of competent jurisdiction in any
     involuntary case brought against a Party under any bankruptcy insolvency or
     other similar law (collectively, "Debtor Relief Laws") generally affecting
     the rights of creditors and relief of debtors now or hereafter in effect,
     (B) the appointment of a receiver, liquidator, assignee, custodian,
     trustee, sequestrator or other similar agent under applicable Debtor Relief
     Laws for a Party or for any substantial part of its assets or property, (C)
     the ordering of the winding up or liquidation of a Party's affairs, (D) the
     filing of a petition in any such involuntary bankruptcy case, which
     petition remains undismissed for a period of 180 Days or which is not
     dismissed or suspended pursuant to Section 305 of the Federal Bankruptcy
     Code (or any corresponding provision of any future United States bankruptcy
     law), (E) the commencement by a Party of a voluntary case under any
     applicable Debtor Relief Law now or hereafter in effect, (F) the consent by
     a Party to the entry of an order for relief in an involuntary case under
     any such law or to the appointment of or the taking of possession by a
     receiver, liquidator, assignee, trustee, custodian, sequestrator or other
     similar agent under any applicable Debtor Relief Laws for a Party or for
     any substantial part of its assets or property, or (G) the making by a
     Party of any general assignment for the benefit of its creditors.

     Barrel shall mean forty-two (42) U. S. Gallons.

     Base Rate shall mean the lesser of (i) two percent (2%) above the per annum
     rate of interest announced from time to time as the "prime rate" for
     commercial loans by First National Bank of Chicago, as such "prime rate"
     may change from time to time, or (ii) the maximum applicable non-usurious
     rate of interest.

     Base Volumes shall mean the minimum Daily volume of Products that CCC will
     agree to 

                                       2
<PAGE>
 
     purchase and WPC will agree to sell and deliver each Month during each
     Delivery Period.

     Business Day shall mean a Day on which Federal Reserve member banks in New
     York City are open for business.

     CCC's Facilities shall mean CCC's Port Arthur chemical plant situated in
     Port Arthur, Texas, and Cedar Bayou chemical plant situated in Baytown,
     Texas.

     Day or Daily shall mean a twenty-four (24) hour period commencing 7:00 a.m.
     local time and extending until 6:59 a.m. local time on the following Day.

     Delivery Month shall mean the Month in which Product(s) are to be delivered
     to CCC as provided herein.

     Delivery Period shall mean a two Month period commencing on the first Day
     of January, March, May, July, September and November of each Year.

     Delivery Point(s) shall have the meaning specified in Section 7.2
     hereinafter.

     Effective Date shall mean September 1, 1996.

     EP Mix shall mean a liquid hydrocarbon stream containing a mixture of
     ethane and propane in the proportions of 80% ethane and 20% propane and
     other associated compounds which meets the specifications set forth in
     Exhibit "A".

     Gallon shall mean the unit of volume used for the purpose of measurement of
     liquid.  One (1) U.S. liquid gallon contains two hundred thirty-one (231)
     cubic inches when the liquid is at a temperature of sixty degrees
     Fahrenheit (60EF) and at the vapor pressure of the liquid being measured.

     Inventory Account shall have the meaning specified in Section 10.1
     hereinafter.

     Month or Monthly shall mean a period commencing at 7:00 a.m. local time on
     the first Day of a calendar month and extending until 6:59 a.m. local time
     on the first Day of the next succeeding calendar month.

     Natural Gasoline shall mean a liquid hydrocarbon stream containing natural
     gasoline and other associated compounds which meets the specifications set
     forth in Exhibit "A".

     New Taxes shall mean any Taxes enacted and effective after the Effective
     Date, including that portion of any Taxes or New Taxes that constitutes an
     increase either in rate or breadth of coverage.

     Normal Butane shall mean normal butane which meets the specifications set
     forth in 

                                       3
<PAGE>
 
     Exhibit "A".

     Offspec Product shall have the meaning specified in Section 8.1
     hereinafter.

     Other Feedstocks shall have the meaning specified in Section 4.4
     hereinafter.

     Party shall mean individually either CCC or WPC (including their respective
     successors and permitted assigns); collectively, the "Parties."

     Person shall mean any individual, corporation, partnership, limited
     liability company, association, joint venture, trust, or other organization
     of any nature or kind.

     Product shall mean EP Mix, Propane, Normal Butane and Natural Gasoline as
     defined herein.

     Propane shall mean a liquid hydrocarbon stream containing propane,
     incidental hydrocarbons and other associated compounds which meets the
     specifications set forth in Exhibit "A".

     Required Inventory shall have the meaning specified in Section 10.2
     hereinafter.

     Renegotiation Notice shall have the meaning specified in Section 5.3
     hereinafter.

     Storage Facility shall mean the underground liquid hydrocarbon storage
     facility located in Mont Belvieu, Texas owned and operated by WPC and being
     the same storage facility previously owned and operated by Warren.

     Taxes shall mean any and all ad valorem, property, occupation, severance,
     production, extraction, first use, conservation, Btu or energy, gathering,
     transport, pipeline, utility, gross receipts, gas or oil revenue, gas or
     oil import, privilege, sales, use, consumption, excise, lease, transaction,
     environmental, and other taxes, governmental charges, duties, licenses,
     fees, permits and assessments.

     Year shall mean a period of twelve (12) consecutive Months commencing from
     the Effective Date.

     1.2  Other Definitions.  Other terms may be defined elsewhere in the text
of this Agreement and shall have the meanings indicated throughout this
Agreement.

                                  ARTICLE II
                        REPRESENTATIONS AND WARRANTIES
                        ------------------------------

     2.1  CCC hereby represents and warrants to WPC that on and as of the date
hereof:

          (a)  It is duly formed and validly existing and in good standing under
               the laws 

                                       4
<PAGE>
 
               of the state or jurisdiction of formation, with all requisite
               corporate power and authority to carry on the business in which
               it is engaged and to perform its respective obligations under
               this Agreement;

          (b)  The execution and delivery of this Agreement have been duly
               authorized and approved by all requisite corporate action;

          (c)  It has all the requisite corporate power and authority to enter
               into this Agreement and perform its obligations hereunder;

          (d)  The execution and delivery of this Agreement does not, and
               consummation of the transactions contemplated herein will not,
               violate any of the material provisions of its organizational
               documents, any material agreement pursuant to which CCC or its
               properties are bound or, to its knowledge, any material laws
               applicable to CCC; and

          (e)  This Agreement is valid, binding, and enforceable against it in
               accordance with its terms, subject to bankruptcy, moratorium,
               insolvency and other laws generally affecting creditor's rights
               and general principles of equity (whether applied in a proceeding
               in a court of law or equity).

     2.2  WPC hereby represents and warrants to CCC that on and as of the date
hereof:

          (a)  It is duly formed and validly existing under the laws of the
               state or jurisdiction of formation, with all requisite power and
               authority to carry on the business in which it is engaged and to
               perform its respective obligations under this Agreement;

          (b)  The execution and delivery of this Agreement have been duly
               authorized and approved by all requisite partnership action;

          (c)  It has all the requisite power and authority to enter into this
               Agreement and perform its obligations hereunder;

          (d)  The execution and delivery of this Agreement does not, and
               consummation of the transactions contemplated herein will not,
               violate any of the material provisions of its organizational
               documents, any material agreement pursuant to which WPC or its
               properties are bound or, to its knowledge, any material laws
               applicable to WPC;  and

          (e)  This Agreement is valid, binding, and enforceable against it in
               accordance with its terms, subject to bankruptcy, moratorium,
               insolvency and other laws generally affecting creditor's rights
               and general principles of equity (whether applied in a proceeding
               in a court of law or equity).

                                       5
<PAGE>

                                                "Confidential Treatment Request.
                                                  The redacted material has been
                                          separately filed with the Commission."


                                  ARTICLE III
                                      TERM
                                      ----

     3.1  Unless otherwise provided herein, this Agreement shall remain in full
* force and effect for a period of REDACTED from the Effective Date hereof and
  shall continue from year to year thereafter unless terminated by either Party
* hereto at the end of such REDACTED period or any yearly anniversary thereafter
  by giving the other Party at least two years advance written notice of its
  intention to so terminate.

     3.2  Notwithstanding Section 3.1 above, this Agreement may be terminated as
follows:

          (a)  By the non-defaulting Party, upon thirty (30) Days written notice
               to the other Party, after it has been determined through the
               alternative dispute resolution procedures of Article XV that a
               Material Default has occurred in the performance of a Party's
               obligations hereunder (it being understood that, for purposes of
               the foregoing, "Material Default" shall mean that the arbitrators
               have determined that (i) in consequence of such default, the
               objectives of this Agreement (as expressed in the Master Alliance
               Agreement of even date herewith by and among CCC, WPC and others)
               are not being met and (ii) the defaulting Party failed to take
               the steps necessary to accomplish such objectives);

          (b)  In the event either Party is dissolved (unless the successor to
               such dissolved Party or its assets is an Affiliate of CCC or WPC)
               or;

          (c)  If a Bankruptcy Event occurs with respect to either Party.

                                 ARTICLE IV
                                 QUANTITY
                                 --------

     4.1  WPC agrees to sell to CCC, and CCC agrees to purchase from WPC on each
day during the term hereof, the Base Volumes as determined and nominated by CCC
in accordance with the procedures set forth in Article VI hereinafter.  In
addition, CCC further agrees to purchase from WPC and WPC agrees to use its best
efforts to sell and deliver to CCC one hundred percent (100%) of CCC's
Additional Volume needs.  It is understood and agreed that all costs and
expenses incurred by WPC in obtaining such Additional Volumes for sale and
delivery to CCC in excess of such costs and expenses that are normally incurred
by WPC in satisfying CCC's Base Volume needs shall be shared by WPC and CCC on
an equal basis.  Prior to incurring any such costs and expenses, WPC will advise
CCC as to its estimate of such costs and will not incur such costs until
approved by CCC.  If CCC is unwilling to pay for its share of such costs, WPC
shall be released from any obligation to supply such Additional Volumes to CCC.

                                       6
<PAGE>

                                                "Confidential Treatment Request.
                                                  The redacted material has been
                                          separately filed with the Commission."

 
     4.2  The Parties hereto recognize that currently, and without spending
additional capital, CCC has no other method to obtain the supply of Product
other than through WPC's equipment and facilities.  The Parties further
recognize that it is intended that WPC be CCC's sole supplier and a preferred
customer of WPC.  Accordingly, WPC agrees that it will advise CCC daily as to
the availability of Products for sale and will work with CCC to manage CCC's
Product supply needs.

     4.3  It is understood and agreed that certain Offspec Product(s) and/or
other opportunistic chemical feedstocks ("Other Feedstocks") may, by mutual
agreement of the parties, intentionally be sold and purchased hereunder.  In
such event, the price, specifications and terms of delivery for such Offspec
Product(s) or Other Feedstocks shall be mutually agreed to by the parties prior
to the delivery of same.

     4.4  The parties hereto recognize and acknowledge that during the term
hereof it may be more economical to both CCC and WPC to import Products, Offspec
Products and/or Other Feedstocks than to purchase same from the Mont Belvieu
market.  If such Products are purchased by WPC for resell to CCC, the price for
such imported Products, Offspec Products and/or Other Feedstocks will be
mutually agreed to by the parties prior to importing same.  It is understood and
agreed that nothing contained in this Article IV is intended to preclude CCC
from obtaining supplies of Products, Offspec Products or Other Feedstocks from
sources outside of the United States as long as the dock and/or other
terminalling facilities owned by WPC or its Affiliates are used to off-load
and/or receive such other Products, Offspec Products or Other Feedstocks at
mutually agreeable rates that are fair and commercially reasonable.

                                   ARTICLE V
                                     PRICE
                                     -----

     5.1  Except as otherwise provided herein, CCC shall pay WPC for (i) the
* Base Volumes purchased hereunder, a price equal to REDACTED as quoted by the
  Oil Price Information Service ("OPIS") for Mont Belvieu, Texas (Non-TET), and
  (ii) any Additional Volumes purchased hereunder, a price mutually agreed to by
  the Parties, and if the Parties are unable to agree upon a price, a price
* equal REDACTED as quoted by OPIS for Mont Belvieu, Texas (Non-TET) for the
  period of time (Days) during each Delivery Month such Additional Volumes are
  delivered to CCC. In addition to the foregoing, for all Products delivered
  hereunder (including the Base Volumes and the Additional Volumes), CCC shall
* pay to WPC a delivery fee (the "Delivery Fee") equal to REDACTED per Barrel.
  For all purposes hereof, delivery of Products shall be deemed to occur at the
  point where title and risk of loss passes to CCC as provided herein.

     5.2  If for any reason the OPIS price for a particular Product should cease
to be published, the parties agree promptly and in good faith to negotiate a
mutually satisfactory

                                       7
<PAGE>

                                                "Confidential Treatment Request.
                                                  The redacted material has been
                                          separately filed with the Commission."

 
alternate index or substitute methodology for calculating the Price for such
Product (the "Alternate Index").  If, on or before thirty (30) Days after the
index used to determine the Price ceases to be available, the parties are unable
to agree on an Alternate Index or substitute methodology upon which to base the
calculation of the Price, the parties shall submit such determination to the
alternative dispute resolution procedures set forth in Article XV hereinafter,
which alternative dispute resolution procedures will determine the Alternate
Index.  From the date on which the index price used to determine the Price for a
particular Product ceases to be available until the Alternate Index is
determined, the Price for such Product shall be the average of the Prices in
effect (or that would have been in effect) during the twelve (12) Months
preceding the Month in which the index upon which the Price was based ceased to
be available, which price shall be effective until the effective date of the
Alternate Index determined as set forth in this Section 5.2.  Upon the
determination of an Alternate Index, the Price will be adjusted retroactively to
the date on which the index upon which the Price previously was based ceased to
be available.

*    5.3  Every REDACTED after the Effective Date of this Agreement, the parties
shall have the option to open this Agreement solely for the purpose of
renegotiating the pricing provisions hereof.  To exercise such option, a party
at least ninety (90) days before the expiration of such  five (5) year period
must provide to the other party written notification (the "Renegotiation
Notice") of its desire to renegotiate the price for the Product sold and
purchased hereunder.  In any such renegotiations, the parties shall continue to
recognize that the price for Product must reflect the prevailing market value of
spot sales and purchases of Product(s) in Mont Belvieu, Texas.  If, after
negotiating in good faith for a period of ninety (90) days following the date of
the Renegotiation Notice, the parties are unable to agree upon a mutually
acceptable price for such Product(s), the matter shall be submitted to the
alternative dispute resolution procedures as set forth in Article XV hereof.
During the period while negotiations are ongoing until (i) a new price is agreed
to or (ii) a new price is established by the alternative dispute resolution
procedures as provided herein, the price for the Product(s) sold and purchased
hereunder shall be determined in accordance with the pricing formula that was
applicable immediately prior to the date of the Renegotiation Notice.  If a new
price is agreed to or is established through the alternative dispute resolution
procedures as provided above, this Agreement shall be amended to reflect such
new price.

     5.4  In the event conditions change such that this Agreement causes, or
could reasonably be expected to cause, a material long term economic or
operational hardship to either Party, upon the written request of either Party,
CCC and WPC shall meet to renegotiate such burdensome terms and provisions so as
to make them fair and equitable.  Such renegotiations shall commence within
thirty (30) days of the written request for such renegotiations.  If the parties
are unable to agree on new provisions to replace such burdensome terms and
provisions within ninety (90) days of the non-requesting party's receipt of such
written request, the matter shall be submitted to the alternative dispute
resolution procedures set forth in Article XV hereof.  It is 

                                       8
<PAGE>
 
understood and agreed that, unless mutually agreed to by the Parties, the rights
granted in this Section 5.4 can only be used by a Party to commence good faith
renegotiations once during each year during the term hereof. If new provisions
are agreed upon under this Section 5.4, whether by renegotiation, mediation,
arbitration or otherwise, such new provisions shall be effective as of, and
shall, if necessary, be made retroactive to, the date on which the notice
commencing renegotiations under this Section 5.4 was given.

     5.5  If, at any time during the term of this Agreement, WPC enters into an
agreement having a term of one year or more with another chemical company to
sell Products and provide the same or similar services at WPC's Mont Belvieu
facilities as WPC provides to CCC as provided herein, WPC agrees to provide the
same overall economic package to CCC.

                                   ARTICLE VI
                                  NOMINATIONS
                                  -----------
                                        
     6.1  On the first Business Day of the Month immediately preceding each
Delivery Period, CCC shall nominate in writing to WPC the Base Volumes to be
purchased by CCC on each Day during such Delivery Period.  If prior to or during
a Delivery Month CCC needs volumes of Product in excess of the Base Volumes
("Additional Volumes"), as soon as reasonably possible prior to the Day CCC
desires for the delivery of such Additional Volumes  to commence, CCC shall
request that such Additional Volumes be supplied by WPC.  Such request may be
verbal if immediately followed in writing by facsimile transmission.

     6.2  Daily and Monthly variations between the Base Volumes nominated by CCC
to be purchased and the volumes taken by CCC shall, as appropriate, be added to
or subtracted from CCC's Inventory Account if, at the time, CCC has sufficient
volumes above the Required Inventory levels in its Inventory Account.  If there
does not exist sufficient volumes in CCC's Inventory Account to allow for such
minor Daily and Monthly variations, any such increases in the volumes of Product
required by CCC shall be deemed Additional Volumes and, if available, shall be
purchased from WPC at a price equal to the average of the daily high and low
prices of each Product as quoted by OPIS for Mont Belvieu, Texas (Non-TET) on
the Business Day such minor variations occurred, if on a Business Day, or the
next succeeding Business Day thereafter if not on a Business Day.

     6.3  CCC shall advise WPC as soon as reasonably possible of any unscheduled
turnarounds at CCC's Facilities and shall give WPC at least twenty four (24)
hours notice prior to the startup of such Facilities following a scheduled or
unscheduled turnaround.

     6.4  To minimize the costs and expenses associated with (i) variances
between the volumes of Base Volumes nominated and the volumes actually taken and
(ii) obtaining the volumes of other Products requested by CCC, CCC and WPC agree
to establish a scheduling committee (the "Scheduling Committee") to perform the
duties as outlined below.  The Scheduling Committee shall be comprised of
members from both CCC and WPC.  CCC and WPC each shall bear their own costs and
expenses associated with the Scheduling Committee and its 

                                       9
<PAGE>
 
activities. The duties of the Scheduling Committee will include, but will not be
limited to, the following:

          (a)  administering and coordinating the routine business of the
               Scheduling Committee including forecasting, planning and
               scheduling of Product deliveries and movements;

          (b)  determining and developing strategies with respect to Scheduling
               Committee activities;

          (c)  developing, monitoring and communicating mutually agreed to
               standards of performance;

          (d)  monitoring the nomination procedures and deliveries of Products;

          (e)  reviewing all significant equipment, design, process and
               operating changes affecting the volumes of Products needed by
               CCC's Facilities;

          (f)  conducting regularly scheduled planning, problem solving and
               expense review meetings;

          (g)  participating in the alternative dispute resolution procedures
               and set forth in Article XV hereinafter;

          (h)  forecasting the availability of Products, Offspec Products and/or
               Other Products and CCC's anticipated needs for same; and

          (i)  aiding in the development of feedstock inventory plans and cost
               risk management programs to assist CCC in lowering its feedstock
               costs and assist CCC in optimizing the flexibility of CCC's
               Facilities.

     6.5  Solely for planning purposes in connection with the management of the
brine supply at WPC's Storage Facility, CCC shall provide to WPC a six (6) Month
rolling estimate of the total inventory of non-LPG feedstocks that CCC will
expect to be stored in WPC's Storage Facility.  For the purpose of this Section
6.5, "non-LPG feedstocks" shall mean Ethylene, Propylene, PP Mix, Naphtha and
other chemical feedstocks.

                                 ARTICLE VII
                                 DELIVERIES
                                 ----------

     7.1  The Product to be sold and purchased hereunder shall be delivered by
WPC  to CCC or to CCC's designated representative for the account of CCC, at the
point(s) of delivery specified herein.  Except as otherwise provided herein, all
Products sold and delivered hereunder shall be used solely by CCC as feedstock
or fuel at CCC's Facilities.

                                       10
<PAGE>

                                                "Confidential Treatment Request.
                                                  The redacted material has been
                                          separately filed with the Commission."

 
     7.2  The point(s) of delivery for Product sold and delivered hereunder
(hereinafter the "Delivery Point(s)") shall be at WPC's Storage Facility and the
delivery of Product shall be deemed to occur (i) at the point at which Product
passes into the pipeline connected to WPC's Storage Facility and designated by
CCC, with respect to Product physically delivered to CCC, and/or (ii) on the
date WPC advises CCC by product transfer order, book transfer, or letter of
transfer, that Product was transferred to CCC's Inventory Account, with respect
to in-storage transfers and Required Inventory purchases by CCC from WPC,

     7.3  For all deliveries of Product from WPC's Storage Facility into a
pipeline designated by CCC, WPC shall operate and maintain equipment to ensure
that the delivery pressure shall be sufficient to allow the Product to enter at
the applicable Delivery Point at the then prevailing operating pressure and flow
rates required therein, which pressure and flow rates shall vary from time to
time, but will not be more than the Maximum Operating Pressure or less than the
Minimum Operating Pressure as set forth in the table below, nor greater than the
flow rates for each Product as set forth below:


          (a) Pipeline(s) Delivering Products on CCC's behalf to Port Arthur:

<TABLE>
<CAPTION>
 
 
          PRODUCT                MINIMUM           MAXIMUM        MAXIMUM FLOW
                                OPERATING         OPERATING           RATE
                                 PRESSURE          PRESSURE
--------------------------------------------------------------------------------
<S>                             <C>               <C>               <C> 
* EP Mix *                       900 psig         1220 psig         REDACTED
--------------------------------------------------------------------------------
</TABLE>
          *    Shall also apply to blends of Ethane and Propane ranging from an
               80/20 mix to a 60/40 mix.

                                       11
<PAGE>

                                                "Confidential Treatment Request.
                                                  The redacted material has been
                                          separately filed with the Commission."

 
(b)  Pipeline(s) Delivering Products on CCC's behalf to Cedar Bayou:

<TABLE>
<CAPTION>
 
          PRODUCT               MINIMUM           MAXIMUM        MAXIMUM FLOW
                               OPERATING         OPERATING          RATE **
                                PRESSURE          PRESSURE
 -------------------------------------------------------------------------------
 <S>                         <C>               <C>               <C>
*Purity Ethane                   550 psig         1440 psig         REDACTED
 -------------------------------------------------------------------------------
 
*EP Mix                          550 psig         1440 psig         REDACTED
 -------------------------------------------------------------------------------

*Propane                         550 psig         1440 psig         REDACTED
 -------------------------------------------------------------------------------
                                                                            
*All Grades of Butane            550 psig         1440 psig         REDACTED 
 -------------------------------------------------------------------------------
                                                                            
*Natural Gasoline                550 psig         1440 psig         REDACTED 
 -------------------------------------------------------------------------------
 
</TABLE>
*         **  WPC shall not be required to deliver more than REDACTED Barrels
              per Day of Product, whether combined or as a single Product.

If CCC's Product needs increase due to expansion or otherwise such that CCC will
require increased flow or delivery rates, upon mutual agreement of the Parties
concerning the reimbursement or sharing of the costs and expenses (if any)
associated with the increase in the flow or delivery rates, the Maximum Flow
Rates as set forth above will be amended.  If the Parties are unable to agree on
the reimbursement or sharing of such costs and expenses, the matter shall be
submitted to the alternative dispute resolution procedures as set forth in
Article XV hereof.

     7.4 Title to and risk of loss associated with the Products sold and
purchased hereunder shall pass from WPC to CCC upon the commencement of the
delivery of such Product at the Delivery Point or when the Product is deemed to
have been delivered as provided in Section 7.2 above.  CCC shall be responsible
for all risk of loss, damage or liability to the extent that any such loss,
liability or damage arises from acts or omissions occurring after the
commencement of physical delivery of the Product at and downstream of the
Delivery Point(s), except for any negligent acts of WPC, its employees, agents
or subcontractors that occur downstream of the Delivery Point(s), and WPC shall
be responsible for all risk of loss, damage or liability to the extent that any
such loss, liability or damage arises from acts or omissions occurring prior to
the commencement of physical delivery of the Product upstream of the 

                                       12
<PAGE>
 
Delivery Point(s), except for any negligent acts of CCC, its employees, agents
or subcontractors that occur upstream of the Delivery Point(s). In the event
delivery of the Product sold hereunder is by in-storage transfer of Product, all
risk of loss, damage or liability shall pass from WPC to CCC at the point in
time when such in-storage transfer shall be deemed to have occurred as provided
in Section 7.2 above, except for any such losses, damages and liabilities that
are caused by the negligence of WPC, its employees, agents or subcontractors.

                                  ARTICLE VIII
                                    QUALITY
                                    -------

     8.1 Except as otherwise provided herein, all Products sold and purchased
hereunder shall meet the specifications set forth in Exhibit A, attached hereto
and made a part hereof.  CCC shall have the right to reject Product which fails
to meet such quality specifications (hereinafter referred to as "Offspec
Product").

     8.2 Should the Product delivered hereunder to CCC, or to CCC's designated
representative for the account of CCC, fail at any time to conform to the
specifications set forth in Exhibit A, each party shall notify the other as soon
as practicable after becoming aware that the Product fails to meet such
specifications, and WPC immediately shall undertake and diligently pursue such
acts as may be necessary to correct such failure so as to deliver Product
conforming to the specifications set forth above; but nothing contained in this
Article VIII or any other part of this Agreement shall be construed to affect
CCC's right, at any time and from time to time, to reject any Product not
conforming to said specifications.

     8.3 The term of this Agreement shall not be extended by the length of time
of any period or periods when deliveries have been rejected, refused or
suspended by CCC as provided for herein.  Notwithstanding the provisions of
Section 8.2 above, if (i) after being given the opportunity to treat and/or
fractionate such Offspec Product, WPC elects not to treat and/or fractionate
same and CCC elects to accept such Offspec Product, or (ii) CCC unknowingly
accepts Offspec Product, the parties will mutually agree upon a discounted price
to be paid by CCC to WPC for such Offspec Product.  In no event shall the
discounted price paid by CCC be less than (y) the price for such specification
Product as set forth in Article V, less $0.022 per Gallon or (z) the price for
such specification Product, less the decrease in the yield value solely caused
by such Offspec Product, whichever is higher.

     8.4 Notwithstanding the specifications of EP Mix set forth in Exhibit A,
WPC agrees to use all reasonable efforts to (i) notify CCC when the methanol
levels in the EP Mix being delivered to CCC exceeds eighty parts per million (80
ppm) (ii) deliver to CCC EP Mix containing less than 80 ppm of methanol, but
will have no liability to CCC for failing to do so after exercising such
reasonable efforts.

                                   ARTICLE IX
                                    WARRANTY
                                    --------

     9.1 WPC warrants title to all Products sold and delivered by it to CCC, and
further 

                                       13
<PAGE>

                                                "Confidential Treatment Request.
                                                  The redacted material has been
                                          separately filed with the Commission."

 
warrants that WPC has the right to sell such Products and that such Products
meet the quality specifications as set forth herein and is free from all liens,
claims or other charges.  UNLESS OTHERWISE PROVIDED IN THIS AGREEMENT, THERE
ARE, NO OTHER WARRANTIES OF ANY KIND WHATSOEVER, EITHER EXPRESS OR IMPLIED,
INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE,
MERCHANTABILITY, CONFORMITY TO MODELS OR SAMPLES, OR OTHERWISE, AND ALL SUCH
WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED BY WPC AND EXCLUDED FROM THIS
AGREEMENT.

                                   ARTICLE X
                                STORAGE SERVICES
                                ----------------

     10.1 Upon execution of this Agreement, CCC shall be deemed to have entered
into a Storage Agreement with WPC, effective as of the Effective Date, pursuant
to the terms and provisions set forth in Exhibit "B" attached hereto and made a
part hereof, pursuant to which CCC will lease Product storage capacity at WPC's
Storage Facility (the "Inventory Account").

     10.2 Each Month during the term hereof, CCC shall maintain in its Inventory
Account the following volumes of inventory of each Product included in the Base
Volumes applicable during the Delivery Period (the "Required Inventory") based
on CCC's Delivery Period nominations:

<TABLE>
<CAPTION>
 
           MONTHS           REQUIRED INVENTORY
  --------------------------------------------
  <S>                       <C>
                           REDACTED
* May through October
  --------------------------------------------
 
* November through April    REDACTED
  --------------------------------------------
</TABLE>

If at any time during a Delivery Month, CCC fails and or refuses to maintain the
Required Inventory for each Product, WPC will have the right, but not the
obligation, to sell such volumes of Product(s) to CCC at a mutually agreed upon
price or, if the parties are unable to agree upon a mutually acceptable price,
at a price equal to the average of the daily high and low prices of each Product
as quoted by OPIS for Mont Belvieu, Texas (Non-TET) on the Day the volumes of
such Product(s) were reduced below the Required Inventory level, if such Day is
a Business Day, or the next succeeding Business Day if such Day is not a
Business Day.

     10.3 Upon CCC's request, WPC will either purchase from CCC volumes of
Product(s) in CCC's Inventory Account at a mutually agreed upon price, or  sell
such Product(s) on CCC's behalf at a mutually agreed upon price or, if the
parties are unable to agree upon a mutually acceptable price, at a price equal
to the average of the daily high and low prices of each Product 

                                       14
<PAGE>
 
as quoted by OPIS for Mont Belvieu, Texas (Non-TET) for the two Business Days
following the Day such request is received by WPC.

                                   ARTICLE XI
                                     TAXES
                                     -----

     11.1 WPC shall be liable for and shall pay, or cause to be paid, or
reimburse CCC, if CCC has paid, all Taxes (other than environmental Taxes, which
environmental Taxes include without limitation, Taxes imposed under Section
4611, 4612, 4661, 4662, 4771 and 4772 and successor sections of the Internal
Revenue Code) applicable to the Product sold hereunder upstream of the Delivery
Point(s).  If CCC is required to remit such Tax, the amount thereof shall be
deducted from any sums becoming due to WPC hereunder.  CCC shall be liable for
and shall pay, cause to be paid, or reimburse WPC, if WPC has paid, all
environmental Taxes and all Taxes applicable to the sale and/or delivery of
Product hereunder at and downstream of the Delivery Point(s) including any Taxes
imposed or collected by a taxing authority with jurisdiction over CCC, provided,
however, when laws, ordinances or regulations permit or impose upon WPC the
obligation to collect or pay Taxes applicable to the sale and/or delivery of
Product hereunder at the Delivery Point, WPC shall collect all such taxes from
CCC, which shall be in addition to the applicable Price, and remit the same to
the appropriate governmental authority, unless CCC furnishes a certificate of
exemption.  WPC and CCC shall indemnify, defend, and hold the other harmless
from and against any liability with respect to the Taxes for which the other
party is liable.

     11.2 While this Agreement remains in effect, CCC shall pay to WPC on
demand, from time to time, all amounts necessary to compensate WPC for any New
Taxes incurred by WPC after the Effective Date of this Agreement applicable to
the sale and/or delivery of Product at and downstream of the Delivery Point(s),
and CCC shall indemnify, defend, and hold WPC free and harmless from and against
any liability with respect to all such New Taxes.  WPC will notify CCC of the
enactment of any New Taxes as promptly as practical after it obtains knowledge
thereof.  WPC will furnish CCC with a statement setting forth the basis and
amount of each request by WPC for compensation under this Section 11.2.

     11.3 To claim an exemption from payment of a Tax, a party shall provide a
certificate of exemption or other reasonably satisfactory evidence of exemption
from any Tax, and each party agrees to cooperate with the other party in
obtaining any such exemption.  In addition, CCC acknowledges receipt of the
disclosure statement from WPC (as set forth in Section 4101 of the Internal
Revenue Code of 1986) or is knowledgeable of the contents thereof.

                                  ARTICLE XII
                            MEASUREMENT AND ANALYSES
                            ------------------------

     12.1    On all deliveries into or out of pipelines, quantities shall be
determined by pipeline meter in accordance with the America Petroleum Institute
("API") Manual of Petroleum Measurement Standards.  For ethane and EP Mix,
volumes of such Products shall be determined (where practical) on a mass (pound)
measurement basis in accordance with the latest edition of 

                                       15
<PAGE>
 
GPA Publications 8173 and 8182. For all other Products, the volumes shall be
determined on a volumetric basis. All quantities shall be corrected to standard
conditions of 60 degrees Fahrenheit and equilibrium vapor pressure in accordance
with the API Manual of Petroleum Measurement Standards, Chapter 14, Section B.
The quantity and quality of Products covered by this Agreement shall be measured
according to the current versions of the applicable standards of API and the
American Society for Testing Materials, if available. Each Party shall be
entitled to have its representatives present during all loadings, unloadings,
tests and measurements involving Products delivered hereunder. If the parties
cannot agree on measurement or quality tests results, the measurements and
quality tests required to determine the volume of receipts or shipments or the
conformity of the Products delivered to the specifications set forth herein
shall be made by an independent inspector selected jointly by the parties, the
cost of which shall be shared equally by the parties.

                                  ARTICLE XIII
                              BILLING AND PAYMENT
                              -------------------

     13.1 Each Month during the term hereof, WPC shall submit an invoice to CCC
by facsimile transmission setting forth the quantity of each Product delivered
during the immediately preceding Delivery Month, the price for such Product, the
amount due hereunder for such quantities, and such other information and detail
as may be mutually agreeable to the Parties.  CCC shall remit by wire transfer
of funds, into an account designated by WPC, any amounts due no later than ten
(10) Days after CCC's receipt of WPC's invoice.  If the Day on which any payment
is due is not a Business Day, then the relevant payment shall be due upon the
immediately preceding Business Day, except if such payment due date is a Sunday
or Monday, then the relevant payment shall be due upon the immediately
succeeding Business Day.

     13.2 If CCC or WPC should fail to remit any amounts in full when due as
required hereunder, or if any adjustments are made under this Agreement,
including, without limitation, adjustments as the result of the conclusion of
any audits or as a result of the resolution of a billing dispute, interest on
the unpaid portion shall accrue from the date upon which such payment should
have been made hereunder until paid in full at the Base Rate.  All such accrued
interest shall be added to the amount reflected as being owed hereunder by
either CCC or WPC, as the case may be, on the next invoice or by separate
invoice.

     13.3 If a good faith dispute arises as to the amount payable in any
statement, the amount not in dispute shall be paid.  If either Party elects to
withhold any payment otherwise due as a consequence of a good faith dispute, the
withholding Party shall provide the other Party with written notice of  its
reasons for withholding payment, and shall simultaneously place the disputed
amount into an escrow account at a mutually acceptable commercial bank, pending
resolution of the dispute.  Any such dispute shall be resolved in accordance
with the alternative dispute resolution procedures of Article XV.  The
performance of both Parties under this Agreement shall continue pending the
outcome of such procedures.  If it is subsequently determined, whether by mutual
agreement of the Parties or otherwise, that the withholding Party is required to
pay all or any portion of the disputed amounts to the other Party, the
withholding Party, in addition to 

                                       16
<PAGE>
 
paying over such amounts, shall also pay interest accrued on such amounts from
the original due date until paid, at the Base Rate.

     13.4  No retroactive adjustments may be made for any overcharge or
undercharge after a period ending twenty-four (24) Months from the end of the
Month in which the invoice or statement forming the basis of the overcharge or
undercharge was delivered or not delivered, as the case may be, unless a claim
for such adjustment shall have been presented prior to the end of such period.
Any payment with respect to a retroactive adjustment shall include an amount
equal to interest on all amounts past due from the date of the initial payment
at the Base Rate, except in instances where neither Party knew or could have
known that the overcharge or undercharge occurred, in which case interest shall
run from the date of demand for payment.  Each Party shall maintain true and
complete records relating to this Agreement and shall retain all such records
for a minimum period of twenty-four Months after the end of the Month in which
Products are delivered.

     13.5  Either Party, upon notice in writing to the other, shall have the
right at reasonable hours to audit the accounts and records relating to the
accounting or billing under the provisions of any article hereof; provided,
however, that the auditing Party must take written exception to and make claim
upon the other Party for all discrepancies disclosed by said audit within
twenty-four (24) Months of the rendition of any statement or invoice forming the
basis of such claim.  Such audit shall be conducted by the auditing Party's
representative or auditor at the auditing Party's expense.

     13.7  ALL DISPUTES ARISING UNDER THIS ARTICLE XIII THAT ARE NOT OTHERWISE
RESOLVED AS PROVIDED HEREIN SHALL BE SUBMITTED TO THE ALTERNATIVE DISPUTE
RESOLUTION PROCEDURES AS SET FORTH IN ARTICLE XV HEREOF.  TO THE EXTENT THAT ANY
SUCH UNRESOLVED DISPUTE HAS NOT BEEN SUBMITTED TO SUCH ALTERNATIVE DISPUTE
RESOLUTION PROCEDURES WITHIN TWENTY-FIVE (25) MONTHS AFTER THE EVENT CAUSING THE
DISPUTE IS DISCOVERED OR REASONABLY SHOULD HAVE BEEN DISCOVERED, THE PARTY
ASSERTING THE CLAIM IN DISPUTE SHALL BE DEEMED TO HAVE WAIVED ANY SUCH CLAIM AND
ALL RIGHTS HEREUNDER WITH RESPECT THERETO.

     13.8  All payments will be made without setoff or counterclaim; provided,
however, that upon a Party's (the "defaulting Party") failure to make payment of
undisputed amounts on the due date, the other Party (the "non-defaulting Party")
may, at its option and in its sole discretion, setoff against any amounts owed
to the defaulting Party, any amounts owed  by the defaulting Party under this
Agreement or otherwise.  The obligations of the non-defaulting Party and the
defaulting Party under this Agreement in respect of such amounts shall be deemed
satisfied and discharged to the extent of any such setoff.  The non-defaulting
Party will give the defaulting Party notice of any setoff made under this
Section 13.8 as soon as practicable after the setoff is made, provided that
failure to give such notice shall in no way affect the validity of the setoff.

                                       17
<PAGE>
 
                                  ARTICLE XIV
                                 FORCE MAJEURE
                                 -------------
                                        
     14.1  In the event either Party is rendered unable, wholly or in part, by
Force Majeure to carry out its obligations under this Agreement, it is agreed
that upon such Party's giving notice and reasonably full particulars of such
Force Majeure in writing to the other Party after the occurrence of the cause
relied on, then the obligations of the Party giving such notice, so far as and
to the extent that they are affected by such Force Majeure, shall be suspended
during the continuance of any inability so caused, but for no longer period, and
such cause shall so far as possible be remedied with all reasonable dispatch.
This Agreement shall not be terminated by reason of any such cause, but shall
remain in full force and effect, and this Agreement shall not be extended
regardless of such curtailment or cessation.  If an event of Force Majeure
results in substantial interference with a Party's performance hereunder and
such condition continues for six (6) consecutive Months or longer, the other
Party shall have the right to terminate this Agreement upon sixty (60) Days
written notice to the other.

     14.2  The term "Force Majeure" as used herein shall mean acts of God,
strikes, lockouts, or other industrial disturbances, acts of the public enemy,
wars, blockades, insurrections, riots, epidemics, landslides, lightning,
earthquakes, fires, tornadoes, hurricanes, or storms, tornado, hurricane, or
storm warnings which in any Parties' judgment require the precautionary shutdown
of either Party's facilities or any operating units thereof, floods, washouts,
arrests or restraints of the government, either federal or state, civil or
military, civil disturbances, explosions, sabotage, breakage or accident to
equipment, machinery or lines of pipe, freezing of machinery, equipment or lines
of pipe, electric power shortages, inability of any Party to obtain necessary
permits and/or permissions due to existing or future rules, orders, laws or
governmental authorities (both federal, state and local), shutdowns due to
explosion or other extraordinary incident, or any other causes, whether of the
kind herein enumerated or otherwise, which were not reasonably foreseeable on
the Effective Date, and which are not within the control of the Party claiming
suspension and which such Party is unable to overcome by the exercise of due
diligence.  It is understood and agreed that the settlement of strikes or
lockouts shall be entirely within the discretion of the Party having the
difficulty, and that the above requirement that any Force Majeure shall be
remedied with all reasonable dispatch shall not require the settlement of
strikes or lockouts by acceding to the demands of opposing parties when such
course is inadvisable in the discretion of the Party having difficulty.  The
term "Force Majeure" shall also include any event of Force Majeure occurring
with respect to the facilities or services of either CCC's or WPC's third Party
suppliers or customers delivering or receiving any product, fuel, feedstock, or
other substance necessary to the performance of such Party's obligations, and
shall also include curtailment or interruption of deliveries or service by such
third Party suppliers or customers as a result of an event of Force Majeure.  It
is expressly agreed by the Parties that neither (i) CCC's inability economically
to use Feedstock purchased under this Agreement nor (ii) WPC's ability to sell
Feedstock to a market at a more advantageous price shall constitute an event of
Force Majeure.

                                       18
<PAGE>
 
                                   ARTICLE XV
                   ALTERNATIVE DISPUTE RESOLUTION PROCEDURES
                   -----------------------------------------

     15.1  Any dispute, controversy or claim arising out of or relating to this
Agreement, or the breach or performance hereof, including, but not limited to,
any disputes concerning the interpretation of the terms and provisions hereof,
shall be resolved through the use of the following procedures or any other
procedures mutually agreed to in writing by the Parties:

          (a)  The parties will initially attempt in good faith to resolve any
               disputes, controversy or claim arising out of or relating to this
               Agreement.

          (b)  Should the Parties directly involved in any dispute, controversy
               or claim be unable to resolve same within a reasonable period of
               time, such dispute, controversy or claim shall be submitted to
               the Scheduling Committee with such explanation or documentation
               as the Parties deem appropriate to aid the Scheduling Committee
               in their consideration of the issues presented.  The date the
               matter is first submitted to the Scheduling Committee shall be
               referred to as the "Submission Date."  The Scheduling Committee
               representatives shall attempt in good faith, through the process
               of discussion and negotiation, to resolve any dispute,
               controversy, or claim presented to it within forty-five (45) days
               after the Submission Date.

          (c)  If the Scheduling Committee representatives cannot so resolve any
               dispute, controversy, or claim submitted to it within forty-five
               (45) days after the Submission Date, the Parties shall attempt in
               good faith to settle the matter by submitting the dispute,
               controversy or claim to mediation within sixty (60) days after
               the Submission Date using any mediator upon which they mutually
               agree.  If the Parties are unable to mutually agree upon a
               mediator within seventy-five (75) days after the Submission Date,
               the case shall be referred for mediation to the office of
               Judicial Arbitration and Mediation Services, Inc. ("JAMS") in
               Houston, Texas. The cost of the mediator will be split equally
               between the Parties unless they agree otherwise in writing.

          (d)  If the matter has not been resolved pursuant to the aforesaid
               mediation procedure within thirty (30) days of the initiation of
               such procedure, or if either Party will not participate in such
               mediation, either Party may request that the matter be resolved
               through arbitration by submitting a written notice (the
               "Arbitration Notice") to the other.  Any arbitration that is
               conducted hereunder shall be governed by the Federal Arbitration
               Act, 9 U.S.C. (S) 1 et seq., and will not be governed by the
               arbitration acts, statutes or rules of any other jurisdiction.

          (e)  The Arbitration Notice shall name the noticing Party's arbitrator
               and shall contain a statement of the issue(s) presented for
               arbitration.  Within fifteen 

                                       19
<PAGE>
 
               (15) Days of receipt of an Arbitration Notice, the other Party
               shall name its arbitrator by written notice to the other and may
               designate any additional issue(s) for arbitration. The two named
               arbitrators shall select the third arbitrator within fifteen (15)
               Days after the date on which the second arbitrator was named.
               Should the two arbitrators fail to agree on the selection of the
               third arbitrator, either Party shall be entitled to request the
               Senior Judge of the United States District Court for the Southern
               District of Texas to select the third arbitrator. All arbitrators
               shall be qualified by education or experience within the natural
               gas, liquefied petroleum gas, natural gas liquids or chemical
               industry to decide the issues presented for arbitration. No
               arbitrator shall be: a current or former director, officer or
               employee of either Party, or its affiliates; an attorney (or
               member of a law firm) who has rendered legal services to either
               Party, or its affiliates, within the preceding three years; or an
               owner of any of the common stock of either Party or its
               Affiliates.

          (f)  The three arbitrators shall commence the arbitration proceedings
               within twenty-five (25) Days following the appointment of the
               third arbitrator.  The arbitration proceedings shall be held in
               Houston, Texas at a mutually acceptable site.  The arbitrators
               shall have the authority to establish rules and procedures
               governing the arbitration proceedings.  Each Party shall have the
               opportunity to present its evidence at the hearing.  The
               arbitrators may call for the submission of pre-hearing statements
               of position and legal authority, but no post-hearing briefs shall
               be submitted.  After the presentation of the evidence has
               concluded, each Party shall submit to the arbitration panel a
               final offer of its proposed resolution of the dispute.  A
               majority of the arbitrators shall approve the final offer of one
               Party without modification, and reject the offer of the other
               Party.  The arbitration panel shall not have the authority to
               award punitive,  exemplary or consequential damages.  The
               arbitrators' decision must be rendered within thirty (30) Days
               following the conclusion of the hearing or submission of
               evidence, but no later than 90 Days after appointment of the
               third arbitrator.

          (g)  The decision of the arbitrators or a majority of them, shall be
               in writing and shall be final and binding upon the Parties as to
               the issue(s) submitted.  The cost of the hearing shall be shared
               equally by the parties, and each Party shall be responsible for
               its own expenses and those of its counsel or other
               representatives.  Each Party hereby irrevocably waives, to the
               fullest extent permitted by law, any objection it may have to the
               arbitrability of any such disputes, controversies or claims and
               further agrees that a final determination in any such arbitration
               proceeding shall be conclusive and binding upon each Party.
               Judgment on the award rendered by the arbitrator may be entered
               in any court having jurisdiction thereof.  The prevailing Party
               shall be entitled to recover reasonable attorneys' fees and court
               costs 

                                       20
<PAGE>
 
               in any court proceeding relating to the enforcement or collection
               of any award or judgment rendered by the arbitration panel under
               this agreement.

          (h)  All deadlines specified herein may be extended by mutual
               agreement of the Parties.  The procedures specified herein shall
               be the sole and exclusive procedures for the resolution of
               disputes between the parties arising out of or relating to this
               Agreement; provided, however, that a Party may seek a preliminary
               injunction or other preliminary judicial relief if in its
               judgment such action is necessary to avoid irreparable damage.
               Despite such action, the Parties will continue to participate in
               good faith in the procedures specified herein.  All applicable
               statutes of limitation, including without limitation, contractual
               limitation periods provided for in this Agreement, shall be
               tolled while the procedures specified in this Section are
               pending.  The parties will take all actions, if any, necessary to
               effectuate the tolling of any applicable statutes of limitation.

                                  ARTICLE XVI
                             LIMITATION OF DAMAGES
                             ---------------------

     16.1  FOR BREACH OF ANY PROVISION FOR WHICH AN EXPRESS REMEDY OR MEASURE OF
DAMAGES IS PROVIDED IN THIS AGREEMENT, SUCH EXPRESS REMEDY OR MEASURE OF DAMAGES
SHALL BE THE SOLE AND EXCLUSIVE REMEDY HEREUNDER, AND THE OBLIGOR'S LIABILITY
SHALL BE LIMITED AS SET FORTH IN SUCH PROVISION, AND ALL OTHER REMEDIES OR
DAMAGES ARE WAIVED.  IF NO REMEDY OR MEASURE OF DAMAGES IS EXPRESSLY PROVIDED
HEREIN, THE OBLIGOR'S LIABILITY SHALL BE LIMITED TO DIRECT ACTUAL DAMAGES ONLY,
EXCLUDING LOST PROFITS, AND SUCH DIRECT ACTUAL DAMAGES SHALL BE THE SOLE AND
EXCLUSIVE REMEDY HEREUNDER, AND ALL OTHER REMEDIES OR DAMAGES ARE WAIVED.  IN NO
EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER PARTY UNDER ANY PROVISION OF
THIS AGREEMENT FOR CONSEQUENTIAL, INCIDENTAL, PUNITIVE, EXEMPLARY, OR INDIRECT
DAMAGES IN TORT, CONTRACT, UNDER ANY INDEMNITY PROVISION OR OTHERWISE.  TO THE
EXTENT ANY PAYMENT REQUIRED TO BE MADE PURSUANT TO ANY PROVISION OF THIS
AGREEMENT IS AGREED BY THE PARTIES TO CONSTITUTE LIQUIDATED DAMAGES, THE PARTIES
ACKNOWLEDGE THAT THE DAMAGES ARE DIFFICULT OR IMPOSSIBLE TO DETERMINE, AND THAT
SUCH PAYMENT CONSTITUTES A REASONABLE APPROXIMATION OF THE AMOUNT OF SUCH
DAMAGES.

                                  ARTICLE XVII
                                 MISCELLANEOUS
                                 -------------

     17.1  This Agreement and the operations hereunder shall be subject to the
valid and 

                                       21
<PAGE>
 
applicable federal and state laws and the valid and applicable orders, laws,
local ordinances, rules, and regulations of any local, state or federal
authority having jurisdiction, but nothing contained herein shall be construed
as a waiver of any right to question or contest any such order, laws, rules, or
regulations in any forum having jurisdiction in the premises. If any provision
of this Agreement is held to be illegal, invalid, or unenforceable under the
present or future laws effective during the term of this Agreement, (i) such
provision will be fully severable, (ii) this Agreement will be construed and
enforced as if such illegal, invalid, or unenforceable provision had never
comprised a part of this Agreement, and (iii) the remaining provisions of this
Agreement will remain in full force and effect and will not be affected by the
illegal, invalid, or unenforceable provision or by its severance from this
Agreement. Furthermore, in lieu of such illegal, invalid, or unenforceable
provision, there will be added automatically as a part of this Agreement a
provision similar in terms to such illegal, invalid, or unenforceable provision
as may be possible and as may be legal, valid, and enforceable. If a provision
of this Agreement is or becomes illegal, invalid, or unenforceable in any
jurisdiction, the foregoing event shall not affect the validity or
enforceability in that jurisdiction of any other provision of this Agreement nor
the validity or enforceability in other jurisdictions of that or any other
provision of this Agreement.

     17.2  THIS AGREEMENT AND THE RIGHTS AND DUTIES OF THE PARTIES ARISING OUT
OF THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED,  ENFORCED, AND PERFORMED
IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS, AS THE SAME MAY BE AMENDED
FROM TIME TO TIME, WITHOUT GIVING EFFECT TO ANY CHOICE OR CONFLICT OF LAW
PROVISION OR RULE THAT WOULD CAUSE THE APPLICATION OF THE LAWS OF ANY
JURISDICTION OTHER THAN THE STATE OF TEXAS.

     17.3  This Agreement, including, without limitation, all exhibits hereto,
integrates the entire understanding between the Parties with respect to the
subject matter covered and supersedes all prior understandings, drafts,
discussions, or statements, whether oral or in writing, expressed or implied,
dealing with the same subject matter.  This Agreement may not be amended or
modified in any manner except by a written document signed by both Parties that
expressly amends this Agreement. No waiver by CCC or WPC of any of the
provisions of this Agreement shall be deemed or shall constitute a waiver of any
other provision hereof (whether or not similar) nor shall such waiver constitute
a continuing waiver unless expressly provided.  No waiver shall be effective
unless made in writing and signed by the Party to be charged with such wavier.

     17.4  The terms, covenants and conditions of this Agreement shall inure to
and be binding upon the parties hereto and their successors and permitted
assigns; provided, however, that neither Party may assign, mortgage, pledge,
encumber or grant a security interest in or a lien on its interest in this
Agreement and/or its rights hereunder in whole or in part without the prior
written consent of the other Party, which consent shall not be unreasonably
withheld, and provided further, that either Party may assign its rights
hereunder to any Affiliate without the approval of the other Party, but any such
assignment shall in no way relieve or release such assigning Party from any
obligations hereunder, whether  accrued or unaccrued, unless agreed to in
writing by the non-assigning Party.

                                       22
<PAGE>
 
     17.5  With the other documents required hereunder, WPC shall provide to CCC
a Material Safety Data Sheet ("MSDS") for each Product delivered hereunder, and
CCC may rely on the information set forth in WPC's MSDS form relating to such
Products.  The foregoing shall not apply to any Other Feedstocks or Offspec
Products that CCC requests be handled by WPC.  CCC and WPC acknowledge that
there may be hazards associated with the loading, unloading, transporting,
handling or use of the Product sold hereunder, which may require that warning be
communicated to or other precautionary action taken with all persons handling,
coming into contact with, or in any way concerned with the Product sold
hereunder. CCC assumes as to its employees, independent contractors, and
subsequent purchasers of the Product sold hereunder all responsibility for all
such necessary warnings or other precautionary measures relating to hazards to
person and property associated with the Product sold hereunder and, furthermore,
CCC shall defend at its own expense, indemnify fully and hold harmless WPC and
its parents, subsidiaries and affiliates and its and their agents, officers,
directors, employees, representatives, successors and assigns from and against
any and all liabilities; losses; damages; demands; claims; penalties; fines;
actions; suits; legal, administrative or arbitration or alternative dispute
resolution proceedings; judgments, orders, directives, injunctions, decrees or
awards of any jurisdiction; costs and expenses (including, but not limited to,
attorneys' fees and related costs) arising out of or in any manner related to
CCC's failure to provide necessary warnings or other precautionary measures in
connection with the Product sold hereunder as provided above.

     17.6  Except as otherwise provided herein, each Party reserves to itself
all rights, set-offs, counterclaims, and other remedies and/or defenses which
such Party is or may be entitled to arising from or out of this Agreement or as
otherwise provided by law.

     17.7  (a)  Each Party agrees that it will maintain this Agreement, all
               terms and conditions of this Agreement, and all other
               Confidential Information (as hereinafter defined) in strictest
               confidence, and that it will not cause or permit disclosure of
               Confidential Information to any third Person without the express
               written consent of the other Party hereto.  Disclosures of
               Confidential Information otherwise prohibited by this Section
               17.7 may be made by either Party:  (i) to the extent necessary
               for such Party to enforce its rights hereunder against the other
               Party; (ii) to the extent a Party is contractually or legally
               bound to disclose information to a third Person (such as a
               shareholder or commercial lender);  (iii) only to the extent to
               which a Party hereto is required to disclose all or part of this
               Agreement by a statute or by the order of a court, agency, or
               other governmental body exercising jurisdiction over the subject
               matter hereof, by order, by regulations, or by other compulsory
               process (including, but not limited to, deposition, subpoena,
               interrogatory, or request for production of documents); (iv) to
               the extent required by the applicable regulations of a securities
               or commodities exchange; or (v) to an Affiliate (but only if such
               Affiliate agrees to be bound by the provisions of this Section).
               "Confidential Information" shall mean any information,
               proprietary to either 

                                       23
<PAGE>
 
               Party and maintained by it in confidence or as a trade secret,
               including, without limitation, business plans and strategies,
               proprietary software, financial statements, customer or client
               lists, personnel records, analysis of general energy market
               conditions, sales, transportation, and service contracts and the
               commercial terms thereof, relationships with current and
               potential business partners, supplies customers, service
               providers and financial sources, data base contents and valuable
               information of a like nature relating to the business of such
               Party. It is understood and agreed that Confidential Information
               shall not include information of a Party that (w) becomes
               generally available to the public at the time of disclosure to
               the other Party, or (x) after the time of disclosure to the other
               Party, was generally made available to the public without breach
               of this Agreement, or (y) the Person receiving the information
               can show was rightfully in its possession at the time of
               disclosure, or (z) was rightfully acquired by the recipient from
               third Persons who did not themselves obtain such information
               under a confidentiality or other similar agreement with the Party
               whose information was disclosed.

          (b)  If either Party is or becomes aware of a fact, obligation, or
               circumstance that has resulted or may result in a disclosure of
               Confidential Information authorized by this Section 17.7, it
               shall so notify the other Party promptly and shall provide
               documentation or an explanation of such disclosure as soon as it
               is available.  Each Party further agrees to cooperate to the
               fullest extent in seeking confidential status to protect any
               Confidential Information so disclosed.

          (c)  The Parties hereto acknowledge that independent legal counsel,
               certified public accountants, or other consultants or independent
               contractors of a Party (collectively, "Outside Consultants") may,
               from time to time, be provided with a copy of this Agreement if,
               in the judgment of the disclosing Party, the information
               contained in this Agreement is necessary to the performance of
               such Outside Consultants' duties.  Accordingly, the Parties agree
               that such disclosure does not require consent by the other Party,
               provided that any such Outside Consultants agree to be bound by
               the provisions of this Section 17.7.

          (d)  Each Party will be deemed solely responsible and liable for the
               actions of its employees, Outside Consultants, officers, and
               agents for maintaining the confidentiality commitments of this
               Section 17.7, but will be required in that regard only to
               exercise such care in maintaining the confidentiality of the
               Confidential Information as such Party normally exercises in
               preserving the confidentiality of its other commercially
               sensitive information.

     17.8  Nothing contained in this Agreement shall be construed to create an
association, 

                                       24
<PAGE>
 
trust, partnership, or joint venture or impose a trust or partnership duty,
obligation, or liability on or with regard to either Party.

     17.9  In construing this Agreement, the following principles shall be
followed:

          (a)  no consideration shall be given to the fact or presumption that
               one Party had a greater or lesser hand in drafting this
               Agreement;

          (b)  examples shall not be construed to limit, expressly or by
               implication, the matter they illustrate;

          (c)  the word "includes" and its syntactical variants mean "includes,
               but is not limited to" and corresponding syntactical variant
               expressions; and

          (d)  the plural shall be deemed to include the singular and vice
               versa, as applicable.

     17.10  Any notice or other communication provided for in this Agreement or
any notice which either Party may desire to give to the other shall be in
writing and shall be deemed to have been properly given if and when sent by
facsimile transmission, delivered by hand, or if sent by mail, upon deposit in
the United States mail, either U.S. Express Mail, registered mail or certified
mail, with all postage fully prepaid, or if sent by courier, by delivery to a
bonded courier with charges paid in accordance with the customary arrangements
established by such courier, in each case addressed to the parties at the
following addresses:


          If to WPC:     WARREN PETROLEUM COMPANY,
                         LIMITED PARTNERSHIP
                         13430 Northwest Freeway, Suite 1200
                         Houston, Texas  77040-6095
                         Attention:  Vice President and General Manager -
                         NGL Marketing
                         Phone: (713) 507-6408
                         Telecopy: (713) 507-3715

                    with a copy to:

                         Vice President & General Counsel
                         WARREN PETROLEUM COMPANY,
                         LIMITED PARTNERSHIP
                         13430 Northwest Freeway
                         Suite 1200
                         Houston, Texas  77040-6095
                         Phone: (713) 507-3725

                                       25
<PAGE>
 
                         Telecopy: (713) 507-6834

          If to CCC:     CHEVRON CHEMICAL COMPANY
                         P. O. Box 3766
                         Houston, TX  77253
                         1301 McKinney Street
                         Houston, TX  77010
                         Attention: Vice President & General Manager -
                         U.S. Chemical Division
                         Telecopy: (713) 754-3077

                    with a copy to:

                         CHEVRON CHEMICAL COMPANY
                         P. O. Box 3725
                         Houston, TX  77253
                         1301 McKinney Street
                         Houston, TX  77010
                         Attention: Associate General Counsel
                         Phone: (713) 754-3319
                         Telecopy: (713) 754-3377

or at such other address as either party shall designate by written notice to
the other.  A notice sent by facsimile shall be deemed to have been received by
the close of the Business Day following the Day on which it was transmitted and
confirmed by transmission report or such earlier time as confirmed orally or in
writing by the receiving party. Notice by U. S. Mail, whether by U. S. Express
Mail, registered mail or certified mail, or by overnight courier shall be deemed
to have been received by the close of the second Business Day after the day upon
which it was sent, or such earlier time as is confirmed orally or in writing by
the receiving party.  Any party may change its address or facsimile number by
giving notice of such change in accordance with herewith.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement the Day
and year first above written.

                              WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP

                              BY:  WARREN PETROLEUM G. P., INC.,
                                   ITS GENERAL PARTNER


                              By:  ____________________________________

                                       26
<PAGE>
 
                              Name: ____________________________________

                              Title:  ____________________________________


                              CHEVRON CHEMICAL COMPANY



                              By:  ______________________________

                              Name: ______________________________

                              Title:  ______________________________

                                       27
<PAGE>
 
                                   EXHIBIT A

       ATTACHED TO AND MADE A PART OF THAT CERTAIN CCC PRODUCT SALE AND
         PURCHASE AGREEMENT BETWEEN WARREN PETROLEUM COMPANY, LIMITED
                   PARTNERSHIP AND CHEVRON CHEMICAL COMPANY


                                 ETHANE-PROPANE
                                 80-20 MIXTURE
                                 SPECIFICATION
                                                            S-200

Product characteristics with test methods are herein specified for ethane-
propane 80-20 mixtures received or delivered by WPC.

<TABLE>
<CAPTION>
 
                                                            TEST METHODS
PRODUCT CHARACTERISTICS                  MINIMUM  MAXIMUM  LATEST REVISION
-------------------------                -------  -------  ---------------
<S>                                      <C>      <C>      <C>
1.   Composition                                             ASTM E-260
     -----------   
     Percent by Liquid Volume
     Methane (Percent of Ethane)                  2.0%       GPA 2177
     Ethylene (Percent of Ethane)                 1.0%
     Methane, Ethane & Ethylene          78.0%    82.0%
     Propane, Propylene & Butanes        18.0%    22.0%      ASTM D-2597
     Propylene                                     1.0%
     Butanes                                       0.8%
 
2.   Corrosion
     ---------
     Copper Strip @ 100EF                          1-b       ASTM D-1838
     (Invalid if additive or
     inhibitor is used.)
     Corrosion Additive or
     Inhibitor, PPMW                               1         Applicable Industry
                                                             Practices

3.   Total Sulfur
     ------------
     PPM by Weight in Liquid                       120       ASTM D-3246
 
4.   Dryness                             No Free Water       Visual
     ------- 
 
5.   Carbon Dioxide
     -------------- 
     PPM by Weight in Liquid                       1,000     GPA 2177
</TABLE>
Product Accounting
------------------
For accounting purposes, methane and ethylene shall be considered ethane,
propylene and butanes shall be considered propane within the above listed
specification limits.

Any excess of these hydrocarbon components above the specification limits shall
not be accounted for.

                                       28
<PAGE>
 
                               HD-5 PROPANE FUEL
                                 SPECIFICATION
                                                            S-300

Product characteristics with test methods are herein specified for HD-5 propane
fuel received or delivered by WPC.  This product meets the requirement of the
GPA HD-5 propane specification.
<TABLE>
<CAPTION>

                                                                                  TEST METHODS
PRODUCT CHARACTERISTICS                  MINIMUM            MAXIMUM             LATEST REVISION
-------------------------                -------            -------             ---------------
<S>                                      <C>                <C>                   <C> 
1.     Composition                                                                ASTM E-260
       ----------- 
       Percent by Liquid Volume                            As limited by other
       Ethane                                              components &           GPA 2177
                                                           vapor pressure.
 
       Propane                             90.0%           100.0%
       Propylene                                           5.0%                   ASTM D-2597
       Butanes & Heavier                                   2.5%
 
2.     Vapor Pressure
       --------------
       Psig @ 100EF                                        208                    ASTM D-1267 (Note 1)
 
3.     Corrosion
       --------- 
       Copper Strip @ 100EF                                1-b                    ASTM D-1838
       (Invalid if additive or
       inhibitor is used.)
       Corrosion Additive or
       Inhibitor, PPMW                                     1                      Applicable Industry 
                                                                                  Practices
4.     Total Sulfur
       ------------
       PPM by Weight in Liquid                             120                    ASTM D-3246
 
5.     Hydrogen Sulfide
       ----------------
       PPM by Weight in Liquid                             1                      Field - Length of
       (Lab test required if field                                                Stain Tube
       test is positive.)                                                         Lab-Gas Chromatography
                                                                                  with Flame Photometric
                                                                                  Detector

</TABLE> 

                                       29
<PAGE>
 
<TABLE>
<CAPTION>
<S>                                      <C>                <C>                   <C> 

6.     Carbonyl Sulfide
       ----------------
       PPM by Weight in Liquid                             2                      Field-Length of
       (Field test invalid if                                                     Stain Tube
       C + exceeds 1.0 IV%)                                                       Lab-UOP 212
        4                                                                             UOP 791
       (Lab test required if field                                                Lab-Gas Chromatography    
       test is positive.)                                                         with Flame Photometric
                                                                                  Detector
 
7.     Non-Volatile Residue
       --------------------
       a)  Milliliters @ 100 (Degrees) F                   0.05                   ASTM D-2158 (Note 1)
       b)  Oil Stain                                       Pass
 
The following tests are optional, depending upon  the product source
--------------------------------------------------------------------
 
8.     Dryness
       -------
       Freeze Valve, Seconds               60              60                     ASTM D-2713
 
9.     Volatile Residue                                    
       ----------------
       95% Evaporated-Temperature, (Degrees)F              -37                    ASTM D-1837
 
10.    Ammonia
       -------
       PPM by Weight in Liquid                             1                      Field-Length of
                                                                                  Stain Tube
                                                                                  Lab-UOP 430
 
11.    Fluorides
       ---------
       PPM by Weight in Liquid as                          5                      Field-Length of
       Monatomic Flourine                                                         Stain Tube
                                                                                  Lab-UOP-619-83 or OI
                                                                                  Analytical or Equal
 
12.    Other Deleterious Substances PPM by Weight in Liquid
       ----------------------------------------------------
       (Includes, but is not limited to,                   1                      Gas chromatography
       Isoprene, Butadiene,                                                       with flame ionization
       Vinyl Chloride, glycol,                                                    or electron capture
       amine, caustic)                                                            detection or other
                                                                                  industry accepted methods
</TABLE> 
NOTE:  (1)  The test methods for items 2 and 7 are not necessary if a
       compositional analysis is available which indicates compliance with these
       requirements.

                                       30
<PAGE>
 
                                 NORMAL BUTANE
                                 SPECIFICATION
                                                            S-400

Product characteristics with test methods are herein specified for normal butane
received or delivered by WPC.
<TABLE>
<CAPTION>
                                                                        TEST METHODS
PRODUCT CHARACTERISTICS                 MINIMUM       MAXIMUM           LATEST REVISION
-------------------------               -------       -------           ---------------
<S>                                     <C>           <C>               <C>
1.   Composition                                                        ASTM E-260
     -----------      
     Percent by Liquid Volume
 
     Isobutanes and Lighter                            5.0%             ASTM D-2597
     Butylene (Percent of N. Butane)                   1.0%
     N. Butane & Butylene               95.0%          100%             GPA 2165
     Pentanes & Heavier                                2.0%
 
2.   Vapor Pressure
     --------------
     Psig @ 100(Degrees)F                              50               ASTM D-1267 (Note 1)
 
3.   Corrosion
     ---------
     Copper Strip @ 100(Degrees)F                      1-b              ASTM D-1838
     (Invalid if additive or
     inhibitor is used.)
     Corrosion Additive or
     Inhibitor, PPMW                                   1                Applicable Industry
                                                                        Practices

4.   Total Sulfur
     ------------
     PPM by Weight in Liquid                           140              ASTM D-3246
 
5.   Volatile Residue
     -----------------------
     95% Evaporated-Temperature, (Degrees) F           +36              ASTM D-1837 (Note 1)
 
6.   Dryness                                       No Free Water        Visual
     -------
 
</TABLE>
NOTE:  (1)  The test methods for items 2 and 5 are not necessary if a
       compositional analysis indicates compliance with these requirements.

                                       31
<PAGE>
 
                                NATURAL GASOLINE
                                 SPECIFICATION
                                                            S-600

Product characteristics with test methods are herein specified for natural
gasoline received or delivered by WPC.
<TABLE>
<CAPTION>
 
                                                                          TEST METHODS
PRODUCT CHARACTERISTICS         MINIMUM         MAXIMUM                 LATEST REVISION
-------------------------       -------         -------                 ---------------
<S>                              <C>             <C>                     <C>
1.   Composition                                                        ASTM E-260
     -----------      
     Percent by Liquid Volume   
     Butanes & Lighter                           3.0%                   GPA 2165
     Butanes & Lighter            97%            100%
 
2.   Vapor Pressure
     --------------
     Psig @ 100(Degrees)F, Reid                  14                     ASTM D-323 (Note 1)
 
3.   Corrosion
     ---------
     Copper Strip @ 104(Degrees)F                1-b                    ASTM D-130
     (Invalid if additive or
     inhibitor is used.)
     Corrosion Additive or
     Inhibitor, PPMW                             1                      Applicable Industry
                                                                        Practices
 
4.   Doctor Test                                 Negative               GPA 1138
     ------------
5.   Dryness                                     No Free Water          Visual (Note 1)
     ------- 
6.   Color                                       No Color               Field White Cup Method
     -----
     Saybolt No.                  Plus 25                               Lab-ASTM D-156
 
7.   Distillation
     ------------
     End Point, (Degrees)F                       375                    ASTM D-216
 
</TABLE> 

NOTE: (1) The test methods for items 2 and 7 are not necessary if an adequate
       compositional analysis is available which indicates compliance with these
       requirements .

                                       32
<PAGE>
                                                "Confidential Treatment Request.
                                                  The redacted material has been
                                          separately filed with the Commission."

 
                                   EXHIBIT B

                  Attached to and made a part of that certain
                    CCC Product Sale and Purchase Agreement
                  between Warren Petroleum Company, Limited 
                   Partnership and Chevron Chemical Company


                           PRODUCT STORAGE AGREEMENT


        This Storage Agreement shall constitute our mutual agreement to lease 
        certain Product storage space facilities owned or controlled by WPC.

        1.      LESSEE:         Chevron Chemical Company

        2.      TERM:           Coterminous with the term of the Master Product
                                Sale and Purchase Agreement to which this
                                Storage Agreement is attached.
         
        3.      PRODUCTS:       80/20 E/P Mix, Propane, Normal Butane, Natural
                                Gasoline and other Products as mutually agreed
                                to by the Parties.
                       
     *  4.     LEASE VOLUME:    REDACTED barrels per Year. For the first Year
                                during the term hereof, the volume leased shall
     *                          be REDACTED Barrels. Annually, during the term
                                hereof, CCC shall have the right to change the
                                volumes leased hereunder within the limits set
                                forth above, upon thirty (30) Days advanced
                                written notice to WPC prior to each anniversary
                                of the Effective Date. CCC shall be allowed one
                                free turn for the volume leased each Year during
                                the term hereof.

*       5.      LEASE RATE:     REDACTED per Barrel per Year for volumes up to
*                               and including REDACTED Barrels, REDACTED per
*                               Barrel per Year for volumes exceeding REDACTED
*                               Barrels up to and including REDACTED Barrels,
*                               and REDACTED per Barrel per Year for volumes
*                               exceeding REDACTED Barrels up to and including
*                               REDACTED Barrels. Additional storage space may
                                be leased during a Year for three Months at a
*                               time at a Lease Rate of REDACTED per Barrel per
                                three Month period.

*       7.      EXCESS STORAGE: REDACTED per barrel based on month end inventory
                                in excess of leased volume. To the extent
                                practicable, WPC and CCC shall

<PAGE>
                                               Confidential Treatment Requested.
                                                The redacted material has been 
                                           separately filed with the Commission.

 
                                agree on excess storage amount prior to storing.

*       8.   RETURN PERCENTAGE: REDACTED on all volumes of Product redelivered,
                                excluding EP Mix. For EP Mix, the return
*                               percentage will be REDACTED on all volumes
*                               redelivered up to REDACTED Barrels per Day and
*                               REDACTED on all volumes redelivered in excess of
*                               REDACTED Barrels per Day.

        9.   PAYMENT TERMS:     Ten (10) days after receipt of invoice.

        10.  RE-OPENER:         This Storage Agreement shall be subject to the
                                provisions of Sections 5.3 and 5.4 of the
                                Agreement to which this Exhibit is attached.