Cambior Inc.
TSX : CBJ
AMEX : CBJ

Cambior Inc.

November 03, 2005 16:20 ET

Cambior's Exploration Update

LONGUEUIL, QUEBEC--(CCNMatthews - Nov. 3, 2005) - Cambior Inc. (TSX:CBJ)(AMEX:CBJ)

Cambior is pleased to provide an update on the exploration results for the La Arena gold property in Peru.

LA ARENA - POSITIVE RESULTS ON THE AU-CU PORPHYRY

The La Arena property is located near the town of Huamachuco in La Libertad department, 480 kilometers north northwest of Lima, Peru. Geologically, it lies within a multimillion ounce gold district that includes the Alto Chicama, Tres Cruces, Shahuindo and Comarsa deposits. The property contains a gold epithermal deposit hosted by highly fractured sandstones of the Chimu formation and a Au-Cu porphyry deposit, directly adjacent to it. An updated resource estimate on the gold epithermal deposit was released earlier this year and showed a 30% increase in measured and indicated resources. Significant mineral occurrences of the same style are known on the rest of the property.

Encouraged by the results released in May 2005 following a first drilling program, the Company initiated a second phase to this program on September 15th 2005. The program included 98 holes totalling 19,280 meters to be drilled on the La Arena concession with the following objectives in mind:



---------------------------------------------------------------------
Zone Program # holes Objective
(m)
---------------------------------------------------------------------
---------------------------------------------------------------------
La Arena Au-Cu
deposit 10,130 33 Deposit evaluation by pattern
drilling on a 100 m section
spacing
---------------------------------------------------------------------
La Arena Au
deposit 3,210 44 Complete the infill drilling
and test remaining open
extensions
---------------------------------------------------------------------
El Alizar Au-Cu
occurrence 2,740 8 Preliminary evaluation of this
porphyry located 1 km west of
the La Arena porphyry
---------------------------------------------------------------------
La Arena property 3,200 13 Drill test significant mineral
occurrences, geochem and
geophysic anomalies on the
rest of the property
---------------------------------------------------------------------
---------------------------------------------------------------------
19,280 98
---------------------------------------------------------------------


The La Arena epithermal and porphyry deposits, covering an area exceeding 3 km2, are part of a multi phased mineralized system displaying potassic and phyllic alteration zones in the porphyry, intermediate sulfidation alteration in the adjacent gold epithermal deposit and overprinting the porphyry and finally hydrothermal and phreatic breccias. La Arena porphyry covers a superficy of more than 2 km X 1 km and has only been drill tested in its central part so far, over a length of approximately 1 km. Additional exploration is required in the north and south extensions.

El Alizar porphyry lies 1 km west of the Arena porphyry and represents a separate porphyry deposit. It has been tested with only one hole so far (03D-LA-109), which showed the presence of gold and copper mineralization within the potassic zone of the porphyry. Surface geochemical sampling also shows gold and copper anomalies coincident with the Alizar porphyry. Induced polarization survey shows similar sizes and geophysical responses for both Alizar and Arena porphyries. This year program includes 8 holes in the Alizar in this porphyry to provide initial evaluation of its potential.

As of October 31st 2005, assays were received for 28 holes totalling more than 11,000 meters drilled. The available results from this drilling program are attached to this press release. A detailed plan view for the La Arena project is also attached. Initial results confirm the presence of gold and copper mineralization with economic potential within the Arena porphyry. Results indicate broad mineralized zones starting at surface and continuous at depths exceeding 350 meters.

The current plan includes completing the drilling program, conducting initial metallurgical studies on the La Arena Au-Cu mineralization, compiling results, geological modelling and initial resource estimation by the end of the first quarter of 2006.

Quality Control

Follow up on the drilling program was carried out by Cambior employees, under the supervision of Louis Gariepy, Geologist, Manager, Exploration-Peru. Mr. Gariepy is a qualified person (as defined by National Instrument 43-101) with more than 20 years of experience in exploration. Cambior has established an Analytical Quality Assurance Program to control and assure the analytical quality of assays in its gold exploration. This program includes the systematic addition of blank samples, field duplicates and certified standards to each batch of samples sent for analysis at commercial laboratories. Blank samples are used to check for possible contamination in laboratories, field duplicates quantify overall precision while certified standards determine the analytical accuracy. Samples were sent for assaying to ALS Chemex Laboratory in Lima, Peru, as a primary lab. Samples were assayed by fire-assay followed by atomic absorption or gravimetry according to industry standards. In addition, 10% of the pulps from the primary lab were sent to a second certified laboratory for analysis.

The La Arena drilling results table and map mentioned in the text are attached to this press release. If you did not receive them, you can download them with this press release from the Cambior website, at www.cambior.com, or you can contact us at the number indicated at the end of this release.

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

Cautionary Note to U.S. Investors -- The United States Securities and Exchange Commission (the "SEC") permits mining companies, in their filings with the SEC, to disclose only those mineral deposits that a company can economically and legally extract or produce. We use certain terms in this press release, such as "mineral resources", that the SEC guidelines strictly prohibit us from including in our filings with the SEC. U.S. investors are urged to consider closely the disclosure in Cambior's Annual Report on Form 40-F. A copy of the 2004 Form 40-F is available to shareholders, free of charge, upon written request addressed to the Investor Relations Department.

Caution Concerning Forward-Looking Statements

This press release contains certain "forward-looking statements", including, but not limited to, statements concerning the current drilling program, the continuing development plan and the type of mineralization present relating to the La Arena project. Forward-looking statements involve a number of risks and uncertainties. There can be no assurance that such statements will prove to be accurate. Actual results and future events could differ materially from those anticipated in such statements. Risks and uncertainties that could cause results or future events to differ materially from current expectations expressed or implied by the forward-looking statements include, among other things, but without limitation, those set forth in Cambior's 2004 Annual Information Form filed with the Securities Commissions of all provinces in Canada, and with the United Stated Securities and Exchange Commission (under Form 40-F), as well as the Toronto Stock Exchange and the American Stock Exchange.

A map of La Arena Property is available at http://www.ccnmatthews.com/docs/cbja1Nov.JPG

La Arena drilling results are available at http://www.ccnmatthews.com/docs/cbja2Nov.pdf

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