Cambior Files Mineral Reserves Report Regarding the Gross Rosebel Gold Property.

Business Editors

LONGUEUIL, Quebec--(BUSINESS WIRE)--Dec. 5, 2001

All amounts are expressed in US dollars

Cambior Inc. (AMEX:CBJ) (TSE:CBJ.) announces that it filed with SEDAR (www.sedar.com), a Mineral Reserves Report on the Gross Rosebel gold property located in Suriname, in accordance with the new National Policy Statement 43-101 for mining projects.

Gross Rosebel's probable mineral reserves, calculated at $300 per ounce of gold, stand at 25.2 million tonnes at an average grade of 1.7 g Au/t, representing 1.3 million ounces of gold contained. The average annual gold production at the Gross Rosebel Property is forecasted at 170,000 ounces with an average direct mining cost of $168 per ounce.

Pre-Feasibility Study

An initial Feasibility Study on the Gross Rosebel Project was completed in November 1997 and was based on conventional open pit mining in both hard rock and soft rock and on a conventional milling operation at 16,000 tonnes per day. An updated pre-feasibility study reduced the scope of the project to include only the mining and processing of soft rock and transition ore, thereby reducing significantly the capital cost of the project to $80 million from the $175 million contemplated in the original 1997 feasibility study.

The new project assumes the development of a 3.6 million tonne per annum conventional carbon-in-leach (CIL) plant and associated infrastructure and services at a capital cost of $40 million. Owner mining of the deposit has been assumed. The capital costs for mining equipment, along with other pre-production costs, tailings impoundment costs, indirect costs, property payments, working capital and an appropriate contingency, aggregates, for the development of the project, $80 million.

The pre-feasibility study and the capital cost estimates were prepared by Cambior's Projects and Construction Group. The following table shows the capital expenditures estimated in the updated pre-feasibility study in comparison with the 1997 feasibility study.

                         CAPITAL EXPENDITURES
                          (in millions of $)

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            Description          1997 Feasibility        Updated
                                      Study          Pre-Feasibility
                                                          Study
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Process Plant                          46.8                 26.2
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Mining equipment and pre-production    46.0                 18.5
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Support Facilities                     30.2                  9.5
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Infrastructure                         14.9                  4.0
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Indirects                              28.1                 12.7
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Contingency                             8.6                  8.7
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Total                                 174.6                 79.6
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Increased Participation in Gross Rosebel to 100%

Cambior announced on October 31, 2001, that it had entered into an agreement with Golden Star Resources Ltd. to acquire its 50% interest in the Gross Rosebel property for a cash consideration of $8 million, and to complete additional transactions regarding OMAI Gold Mines Limited, the Yaou and Dorlin properties in French Guiana and other exploration properties located in the Guiana Shield. With the closing of this transaction, which is expected shortly, Cambior will benefit from a strong synergy in the Guiana Shield and plans to further reduce the above $80 million capital expenditures through the transfer of available equipment from the Omai mine.

The Gross Rosebel project is the most important undeveloped property in the Guiana Shield and Cambior is committed to pursuing its development. Meetings are presently being held with the Government of Suriname to confirm availability of electric power and costs, review of Grassalco's participation in the project, and to establish a Surinamese operating company. Once these matters and other issues will have been resolved, Cambior will proceed to close its transaction with Golden Star and, thereafter, intends to complete a final feasibility study by mid-2002 and prepare this low-operating cost project for construction by the end of 2002.

Mineral Reserves Report ("Technical Report")

Most of the exploration work followed a systematic sequence of regional prospecting and mapping followed by extensive augering and diamond drilling over promising targets. One hundred metre - spaced trenches over the mineralized zones provided abundant structural information. By the end of August 1997, more then 108,000 metres of diamond drilling were completed and 166,555 samples were collected on the property. The metallurgical test work was completed by Lakefield Research Laboratory (Ontario), Hazen Research Laboratory (Colorado) and Mineral Resource Development (Colorado).

The key assumptions for the study included the above capital cost estimates, a gold price of $300 per ounce, royalties of 2.25%, operating experience and operating cost information from the Omai mine in Guyana, and the supply of power from the hydroelectric grid from the Afobaka Dam, at a base cost of $0.03 per kWh (variable as per the market price of gold). The following table summarizes the key parameters for the project, compared with the parameters from the 1997 feasibility study.

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              Parameter                     1997           Updated
                                        Feasibility   Pre-Feasibility
                                           Study(1)          Study
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Strip ratio                                  3.0               2.0
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Probable mineral reserves (million tonnes)  48.6              25.2
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Diluted grade (g Au/t)                       1.6               1.7
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Gold recovery (%)                             93                92
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Total gold contained (ounces)          2,500,000         1,350,000
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Milling rate (tonnes per day)             16,000            10,000
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Mine life (years)                              9                 7
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Total capital costs ($ million)              175                80
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Average cash costs (US$/ounce)               229               168
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(1) Mineral resource estimate in 1997.

      Qualified Persons

      Mineral reserve and resource estimates have been calculated by
Cambior's technical personnel in accordance with definitions and
guidelines adopted by the Canadian Institute of Mining, Metallurgy,
and Petroleum (CIM - "Standards on Mineral Resources and Reserves") in
August 2000. There are numerous uncertainties inherent in estimating
mineral reserves, including many factors beyond the Company's control.
Assessing mineral reserves is a subjective process, and the accuracy
of any reserve estimate is a function of the quality of available data
and of engineering and geological interpretation and judgement.
Results from drilling and testing, as well as material changes in
metal prices subsequent to the date of an estimate, may justify
revision of such estimates.
      Qualified persons(1) responsible for the mineral reserve and
resource estimates along with the metallurgy and capital cost
estimates for the Gross Rosebel Project are as follows:

Mineral reserve estimate        K. Atherton      Engineering
                                                 Superintendent
                                                 Omai Gold Mines Ltd.
Block model, exploration
 program, geology               F. Viens         General Manager,
                                                 mining geology
Metallurgy                      C. Dufresne      Mill Superintendent
                                                 Omai Gold Mines Ltd.
Capital cost-construction       R. Menard        Vice President -
                                                 Construction
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The Form 43-101F - Technical Report on the Gross Rosebel project is filed with this press release on the SEDAR website at www.sedar.com.

Cautionary Note to U.S. Investors - The United States Securities and Exchange Commission ("SEC") allows mining companies, in their continuous disclosure filings with the SEC, to disclose only those mineral deposits that a company can economically and legally extract or produce. Certain terms used in this document, such as "mineral resources," that the SEC guidelines strictly prohibit from including in Cambior's filings with the SEC. U.S. investors are urged to consider closely the disclosure in Cambior's Annual Report on Form 20-F. A copy of this form is available to shareholders, free of charge, upon written request addressed to the Investor Relations Department.

Cambior Inc. is an international gold producer with operations, development projects and exploration activities throughout the Americas. Cambior's shares trade on the Toronto (TSE) and American (AMEX) stock exchanges under the symbol "CBJ".

This press release contains certain "forward-looking statements", as defined in the United States Private Securities Litigation Reform Act of 1995, that involve a number of risks and uncertainties. There can be no assurance that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. Such risks and uncertainties are disclosed under the heading "Risk Factors" in Cambior's 2000 Annual Report on Form 20-F filed as its Annual Information Form with the securities commissions of all provinces in Canada, and with the United States Securities and Exchange Commission, as well as the TSE and the Amex.

(1)Qualified person: individual who is an engineer or geoscientist with at least five years of experience in mineral exploration, mine development or operation, mineral project assessment, or any combination of these; such individual has experience relevant to the subject matter of the mineral project and the technical report, and is a member in good standing of a professional association.