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Exhibit 10.20
  *** indicates confidential portions have been
 redacted and submitted separately pursuant to
 confidentiality request with the Commission
   AGREEMENT
    FOR THE EXCLUSIVE SUPPLY OF STYRENE
    TEXAS CITY  TEXAS
    Dated September 17, 2007
    By and between
    STERLING CHEMICALS, INC.
    and
    NOVA CHEMICALS INC.




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(Producer) (Customer)
 
    1.
    Definitions
    and Interpretation  1.1  Definitions
    AAA
  AAA Rules
  Acquisition Transaction (Styrene Monomer Business)
 
  Affected Party (Event of Force Majeure)
 
  Affiliate control and/or controlled controlling
  Agreement
  Applicable Law
 
  Assigned Contracts (Other Matters)
 
  Authorization
  Business Day
  Claims
  Confidential Information
   
  and/or (Permitted
    Disclosure)
 
  Consequential Loss provided however
 2




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Contract
  Customer
 
  Customer Indemnified Person (Indemnification of Customer)
 
 
  Defaulting Party (Losses)
 
  Default Rate
  Dispute
 
  Dispute Notice (Amicable Settlement)
 
 
  Effective Date (Conditions)
 
 
  EFT (Invoicing)
 
  Environmental Damages Product Schedule A Schedule A
 3




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Environmental Law
 
  Events of Force Majeure (Events of Force Majeure)
 
 
  Force Majeure (Force Majeure)
 
 
  FTC (Conditions)
 
  Governmental Entity
  Hazardous Materials et seq et seq
  HSR Act Hart-Scott-Rodino
 
  Indemnified Party (Indemnification Procedures)
 
 
  Indemnifying Party (Indemnification Procedures)
 
  Insolvency Event
       4




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Inventory
 
  Invoice (Invoicing)
 
  Joint Venture
  Law
  Loss
  Marine Provisions
  Month
 
  Newly Imposed Tax (Tax)
 
 
  Non-Affected Party (Notification)
 
 
  Non-Defaulting Party (Losses)
 
  Party
  Person
 
  Point of Delivery (Title and Transfer; Point of
    Delivery)
 
 
  Price (Invoicing)
 
 5




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Proceedings
  Producer
  Product Schedule A
  Release Releases
  Tax
  Tax Deduction
  Term
 
  Termination Event (Termination Events)
 
  Texas City Styrene Plant
 
  Third Party Claim (Indemnification Procedures)
 
  1.2  Interpretation
           
   
  include including
  official
    requirement
  2.
    Term  Term
 6




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3.
    Supply of
    Product 
  3.1  Exclusivity
 
    3.2  Quantity
  Maximum Quantity (Nomination; Shut Down or Decommission) (Nomination)
  3.3  Standard
    of Performance
    4.
    Nomination;
    Shut Down or Decommission  4.1  Outages
        4.2  Nomination
     7




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5.
    Delivery,
    measurement and testing  5.1  Delivery
    Rate
    5.2  Title
    and Title Transfer; Point of Delivery
  Point of Delivery
 8




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5.3  Measurement,
    Sampling and Analysis
    6.
    Non-Refundable
    Capacity Reservation Charge; Product Price  6.1  Capacity
    Reservation Charge
  (Covenant not to Compete)
  6.2  Product
    Price
  *** ***
  7.
    Payment
    and Invoicing  7.1  Invoicing
  Invoice EFT
   9




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7.2
    Payment
    Procedure    7.3
    Disputed
    Payments    (Late Payment)
    7.4  No
    Deductions
    7.5  Tax
  Newly Imposed
    Tax
  7.6  Late
    Payment
    7.7  Suspension
    of Supply of Product for Non-Payment
  (Suspension of Supply of Product for Non-Payment)
 10




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##### 



(Default) (Termination)
  8.
    Force
    Majeure  8.1  Event
    of Force Majeure
  Affected Party Events of Force
    Majeure
    8.2  Notification
  Non-Affected Party
  8.3  Legal
    Effects
  (Notification)
  8.4  Financial
    Consequences
  (Legal Effects)
  8.5  Alternative
    Arrangements
   11




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8.6  Termination
    for Extended Force Majeure
      (Legal
    Effects)
  8.7  No
    Liability for Force Majeure Termination
  (Survival of Rights,
    Duties and Obligations) (Termination for
    Extended Force Majeure)
  9.
    Representations
    and Warranties    9.1  Status
      9.2  Powers
    9.3  Authorization
    and Consents
    9.4  Non-Violation
   12




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9.5  Obligations
    Binding
    9.6  Litigation
  and/or
  9.7  No
    Judgments
    9.8  No
    Reliance
    9.9  Product
  Schedule A
  9.10  Assignments
  (Indemnity)
  10.
    Default  10.1  Losses
  Defaulting Party Non-Defaulting Party
  10.2  Exclusion
    of Consequential Loss
  EXCEPT AS
    OTHERWISE EXPRESSLY PROVIDED IN THIS AGREEMENT, IN NO EVENT
    SHALL EITHER PARTY BE LIABLE TO THE OTHER PARTY (EVEN IF
    NEGLIGENT) FOR ANY
 13




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CONSEQUENTIAL LOSSES UNLESS (a) SUCH CONSEQUENTIAL
    LOSSES RESULT FROM THE GROSS NEGLIGENCE OR INTENTIONAL
    MISCONDUCT OF SUCH PARTY OR (b) SUCH CONSEQUENTIAL LOSSES
    ARE PAYABLE BY AN INDEMNIFIED PERSON PURSUANT TO A THIRD PARTY
    CLAIM FOR WHICH INDEMNIFICATION IS AVAILABLE HEREUNDER.
  10.3  Mitigation
    10.4  Quantification
    of Damages
  (Disputes)
  10.5  Exclusive
    Remedies
  (Exclusive Remedies)
  11.
    Conditions  Effective Date
  FTC
  (Notices) provided however
   14




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Antitrust
    Division
    12.
    Termination  12.1  Termination
    Events
  Termination Event)
        12.2  Right
    to Terminate
  (Notices)
  12.3  Entitlement
    on Termination
    12.4  Sole
    Rights of Termination
  (Term) (Shutdown) (Termination for Extended
    Force Majeure) (Conditions) (Termination)
 15




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13.
    Indemnity  13.1  Indemnification
    of Customer
  Customer Indemnified Persons
                  (Title and Title Transfer; Point of Delivery)
      13.2  Indemnification
    of Producer
  Producer
    Indemnified Persons
     16




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13.3  Indemnification
    Procedures
  Indemnified Party (Indemnification of Customer) (Indemnification of Producer) Indemnifying
    Party Third Party
    Claim
  13.4  Defense
    of Third Party Claim
  (Indemnification Procedures) (Defense
    of Third Party Claim)
  13.5  Payment
  (Indemnity) and/or
 17




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14.
    Assignment  provided however
  15.
    Confidentiality  15.1  Obligation
    of Confidentiality
  (Permitted Disclosure) (Obligation of Confidentiality)
  (Confidentiality)
            (Disputes)
  15.2  Permitted
    Disclosure
       18




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(Permitted Disclosure)
    15.3  Third
    Parties
  (Confidentiality) (Permitted
    Disclosure) (Confidentiality)
  15.4  Damages
    Not an Adequate Remedy
  (Confidentiality)
  16.
    Environmental
    Health & Safety  16.1 (Title and Title Transfer; Point of
    Delivery)
  16.2
  16.3
  17.
    Other
    Matters  Customer Contracts Assigned Contracts
 19




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18.
    For
    Greater Certainty  18.1  No
    Ownership or Interest of Customer
    18.2  Customer
    and Supplier Relationship
            18.3  Accounts
    Receivable and Inventory
   20




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18.4  No
    Real Property Ownership
    18.5  Producer
    Purchase Contracts
    18.6  Other
    19.
    Covenant
    Not To Compete      Acquisition Transaction
   21




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20.
    Notices  next-day
  Producer: Sterling Chemicals, Inc.
  (713) 654-9577
  Customer: NOVA Chemicals Inc.
  
  21.
    Disputes  21.1  Amicable
    Settlement
  Dispute Notice
  21.2  Arbitration
  (Amicable Settlement) AAA
    Rules (Arbitration)
 22




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21.3  Litigation;
    Exclusive Jurisdiction; Waiver of Jury Trial
  (Arbitration)
 23




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##### 



22.
    Miscellaneous  22.1  Survival
    of Rights, Duties and Obligations
  (Definitions
    and Interpretation) (Capacity Reservation
    Charge) (Product Price) (Payment and
    Invoicing) (Exclusion of Consequential Loss) (Conditions) (Environmental Health &
    Safety) (No Ownership or Interest of Customer) (Covenant Not to Compete) (Notices) (Disputes) (Miscellaneous) (Governing Law)
  22.2  Variation
    and Amendment
    22.3  Waiver
    22.4  Partial
    Invalidity
    22.5  No
    Partnership
    22.6  Entire
    Agreement
   24




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22.7  Counterparts
    22.8  Costs
    22.9  Rights
    of Third Parties
    23.
    Governing
    Law    [Signatures
    on Next Page.]
 25




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##### 



PRODUCER:
  Sterling Chemicals, Inc.
  By:
    /s/  Richard
    K. Crump     CUSTOMER:
  NOVA Chemicals Inc.
  By:
    /s/  Jeffrey
    M. Lipton      By:
    /s/  J.
    Alan Crittenden    26




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Schedule A
  Styrene
    Specifications
  Astm MethodCharacteristic

Specification

NumberAppearance

Clear & Free

602.282(1)Color

15 max

D5386Polymer, ppmw

10 max

D2121-AAssay, wt%

99.85 min

D5135Inhibitor (TBC), ppmw

10  15(2)

D4590Aldehydes (as benzaldehyde), ppmw

200 max(3)

D2119Peroxides, ppmw

100 max(3)

D2340Sulfur, ppmw

5 max(3)

D3961Chlorides, ppm

10 max

D5808Ethylbenzene, wt%

0.015 max

D5135Benzene, ppmw

1.0 max(3)

602.062(1)     (1)
    
    Producer method(2)
    
    or as specified(3)
    
    guaranteed analysis 27