**Exhibit 99.4**

 
|                           | **Ernst**& **Young LLP** |                                       | Phone: 403 290-4100 |
|---------------------------|------------------------------|--------------------------------------------|---------------------|
| **Chartered Accountants** |                         | Fax:     403  290-4265 |
|                      | Ernst & Young Tower      |                                       |                |
|                      | 1000 440 2 Avenue SW         |                                       |                |
|                      | Calgary AB Canada T2P 5E9    |                                       |                |

 

**Consent of Independent RegisteredPublic Accounting Firm**

 

We consent to use of our reports dated February 15, 2006 with respectto the consolidated financial statements of NOVA Chemicals Corporation for theyears ended December 31, 2005, 2004 and 2003, NOVA Chemicals Corporationmanagement’s assessment of the effectiveness of internal control over financialreporting, and the effectiveness of internal control over financial reportingof NOVA Chemicals Corporation, included in an exhibit to the Annual Report(Form 40-F) for 2005, filed with the Securities and Exchange Commission. 

 

We consent to the incorporation by reference in the followingRegistration Statements:

 

(1)          Registration Statement(Form S-8 No. 333-101793) pertaining to the Employee Savings and Profit SharingPlan for Canadian Employees, the Director Share Unit Plan, the Deferred ShareUnit Plan for Key Employees, the Deferred Share Unit Plan for US Key Employeesand the Deferred Share Unit Plan for Non-Employee Directors of NOVA ChemicalsCorporation, and the Employee Savings and Profit Sharing Plan for US Employees,the US Savings and Profit Sharing Restoration Plan and the Capital AccumulationPlan of NOVA Chemicals Inc.

(2)          Registration Statements(Form S-8 Nos. 33-47673, 333-520, 333-9076 and 333-12910) pertaining to theEmployee Incentive Stock Option Plan (1982) of NOVA Chemicals Corporation

(3)          Registration Statement(Form S-8 No. 333-9078) pertaining to the Employee Savings and Profit SharingPlan for Canadian Employees of NOVA Chemicals Corporation

(4)          Registration Statement(Form S-8 No. 33-86218) pertaining to the Employee Savings and Profit SharingPlan for NOVA Chemicals Inc. (formerly Polysar Incorporated)

(5)          Registration Statement(Form S-8 No. 33-77308) pertaining to the Director Share Purchase Plan of NOVAChemicals Corporation

(6)          Registration Statement(Form S-8 No. 333-11280) pertaining to the Beaver Valley Hourly Plan of NOVAChemicals Corporation

(7)          Registration Statement(Form S-8 No. 333-109424) pertaining to the Restricted Stock Unit Plan of NOVAChemicals Corporation

 

of our reports dated February 15, 2006 with respect to the consolidatedfinancial statements of NOVA Chemicals Corporation for the years ended December31, 2005, 2004 and 2003, NOVA Chemicals Corporation management’s assessment ofthe effectiveness of internal control over financial reporting, and theeffectiveness of internal control over financial reporting of NOVA ChemicalsCorporation, included in the Annual Report (Form 40-F) for the year endedDecember 31, 2005.

 

 
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| Calgary, Canada |   |                  |
| March 1, 2006   |   | Chartered Accountants |

 

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