Osisko Tables Preliminary Assessment Study On Canadian Malartic Project

MONTREAL, QUEBEC, Mar 31 (MARKET WIRE) --
Osisko Exploration Ltee. (TSX: OSK)(Deutsche Boerse:EWX) is pleased to
announce results of the Preliminary Assessment Study (the "Study") of its
100% owned Canadian Malartic Gold Project located in Malartic, Quebec.
The Study was compiled by BBA Inc., with the collaboration of RSG Global
Consulting, G Mining Services, Genivar, Golder Associates and the Osisko
Technical Group. Osisko released its current inferred resource of 8.4M oz
gold in mid-2007 (see July 5, 2007 press release). For the purposes of
this Preliminary Assessment Study, only in-pit inferred resources between
surface and a vertical depth of 400 metres were considered. A gold price
of $775 per ounce was assumed for the financial analysis, and current
market prices for all materials were applied. All dollar amounts
presented in this press release are expressed in US dollars. An exchange
rate of 1.10 was used with respect to Canadian expenditures.

Results of the Study are highly encouraging and Osisko is continuing to
work towards definitive feasibility on the Canadian Malartic Project,
expected to be delivered by year end. The Study shows that over the first
three years of production, Canadian Malartic will average 572,000 ounces
of gold per year at an average head grade of 1.05 g/t Au and with cash
costs averaging $314 per ounce (including royalties). Over the first
three years, the operation would generate pre-tax cash flow of $731 M.
Over a projected 14 year mine life the current deposit would produce an
average of 457,800 ounces of gold per year at an average cash cost of
$381 per ounce (including royalties), generating pre-tax operating cash
flow of $2.58 billion, with over $1 billion pre-tax cash flow generated
in the first five years of production. The Study shows an Internal Rate
of Return (using a 5% discount rate) of 22.2 percent and possible Payback
Period of 39 months.

Summary highlights of the Study are shown in the table below:

------------------------------------------------------------------------
Estimated Mined Gold (oz) 7,794,000 (Whittle Pit constrained)
------------------------------------------------------------------------
Estimated Net Recoverable Gold (oz) 6,547,000 (based on 84% recovery)
------------------------------------------------------------------------
Average Annual Gold Production (oz) 457,800 (572,000 - Years 1 to 3)
------------------------------------------------------------------------
Cash Cost per ounce
- before royalties $369 ($ 301 - Years 1 to 3)
- with royalties $381 ($ 314 - Years 1 to 3)
------------------------------------------------------------------------
Initial investment (CAPEX) $760 M
------------------------------------------------------------------------
CAPEX per ounce $116
------------------------------------------------------------------------
Sustaining Capital $59 M
------------------------------------------------------------------------
Closure Costs $52 M
------------------------------------------------------------------------
Operating Cash flow pre-tax $2,582 M
------------------------------------------------------------------------
IRR - pre-tax (5% discount) 22.2%
------------------------------------------------------------------------
Payback 39 months
------------------------------------------------------------------------
Mine Life 14.3 Years
------------------------------------------------------------------------

Capital expenditures are estimated at $760 M (which includes
contingency of $72.6 M), giving the project a capital expenditure per
recoverable ounce of $116, within current industry norms for the best
gold projects in the world. Osisko has already paid approximately $30 M
towards capital expenditures in the form of capital equipment purchases
(milling equipment) and the relocation plan (home and land purchases and
initial Sector 7 development), leaving remaining capital investment
requirement of the project at approximately $733 M (including contingency
of $72.6 M). It is also estimated that only 15 percent of operating costs
will be diesel purchases, limiting the project exposure to rising oil
prices.

Sean Roosen, President and CEO of Osisko commented: "We are very pleased
with the positive results of our Preliminary Assessment Study. Canadian
Malartic continues to demonstrate that it is a solid world class gold
project in what the 2007 Fraser Institute survey indicates is the best
mining jurisdiction in the world. At $116 per ounce of construction and
development costs, we are in line with other similar sized projects
globally. While our capital outlay estimate reflects the increased cost
pressure that all new projects have been facing in the current market
environment, we believe that our early call in procuring our SAG mill,
initial two ball mills and other ancillary equipment minimizes the impact
of the inflation experienced by our industry. We are now moving forward
quickly toward our goal of making Osisko the next premium intermediate
gold producer, with no legacy issues and very limited exposure to either
geopolitical or energy cost volatility.

The Study shows that on its own, the main deposit provides strong returns
in the current environment. It will be the foundation for further growth
of the Company through the drill definition of new resources on our
current targets, potential new discoveries in other areas on our large
land position, and the possibility of new acquisitions within trucking
distance from our proposed mill site.

Over the next twelve to eighteen months we will be drill-defining several
of our near-surface mineralized zones that have the potential to provide
higher grade resources for blending opportunities and increased early
debt pay-down, such as the South Barnat Zone. We will also look at deeper
targets as we have only really explored to depths of 400 meters to date."

Location

The Canadian Malartic Project is located 25km west of Val d'Or in the
rich gold mining district between Val d'Or and Cadillac. The Project is
easily accessible by road being located near highway 117 and is serviced
by a railway. Electrical power is easily accessible with the Project
being located within 9km from Hydro-Quebec's electrical power grid. The
region also benefits from a strong contractor and supplier base to the
mining industry and an experienced mining workforce. The greater Malartic
area produced some 8.7 M ounces of gold during the period ranging from
1938 to 1983.

Capital Investment Program

The initial capital investment program amounts to US $760 M and is
summarized below:

---------------------------------------------------------------------
Mining - Equipment $92.9 M
- Pre-production $22.2 M $115.1 M

Mineral Processing Plant $351.0 M

Tailings and Water Management $27.9 M

Electrical and Communication $19.7 M

Administration Buildings and Infrastructure $29.2 M

Community Development and Relocation Program $82.0 M

Indirects $51.5 M

Owner's Cost $11.0 M
---------------------------------------------------------------------
$687.4 M

Contingency $72.6 M
---------------------------------------------------------------------
Total $760.0 M

The Company has entered into commitments on many long-lead items and
has received firm quotations which it expects to execute within the next
30 days for total purchases of $200 M. Accordingly, no contingency has
been applied to those purchases. A contingency provision of 15% has been
estimated on the remaining project outlays. The level of accuracy of the
capital investment estimate is +/- 25%.

The investment program is scheduled over a two year period. Sustaining
capital is estimated at $59 M and mainly for additional mining equipment.
Closure cost provisions amount to $52 M.

Mining

The preliminary mining plan has been established using the inferred
resources calculated by RSG Global Consulting Pty. Ltd. An open pit
optimization was performed using Whittle software, which is based on the
Lerchs-Grossmann algorithm. The pit optimization resulted in an estimated
mining resource conversion rate of 92 percent relative to the published
inferred resource.

Summary of the annual mining excavation plan is as follows:

--------------------------------------------------------------------------
Period Ore mined Waste mined Total Mined Stockpile Reclaim Total moved
(kt) (kt) (kt) (kt) (kt)
--------------------------------------------------------------------------
-1 6,568 8,432 15,000 15,000
--------------------------------------------------------------------------
1 24,193 23,807 48,000 48,000
--------------------------------------------------------------------------
2 28,715 19,285 48,000 48,000
--------------------------------------------------------------------------
3 18,071 29,929 48,000 5,921 53,921
--------------------------------------------------------------------------
4 16,482 31,518 48,000 3,594
51,594--------------------------------------------------------------------------
5 16,104 33,896 50,000 3,970 53,970
--------------------------------------------------------------------------
6 15,627 34,373 50,000 4,448 54,448
--------------------------------------------------------------------------
7 18,747 31,253 50,000 1,328 51,328
--------------------------------------------------------------------------
8 22,116 27,884 50,000 50,000
--------------------------------------------------------------------------
9 23,541 26,459 50,000 449 50,449
--------------------------------------------------------------------------
10 18,446 16,554 35,000 1,776 36,776
--------------------------------------------------------------------------
11 19,731 15,269 35,000 345 35,345
--------------------------------------------------------------------------
12 20,501 14,499 35,000 35,000
--------------------------------------------------------------------------
13 21,793 13,207 35,000 35,000
--------------------------------------------------------------------------
14 17,062 7,888 24,950 3,400 28,350
--------------------------------------------------------------------------
15 6,647 6,647
--------------------------------------------------------------------------
Total 287,697 334,253 621,950 31,878 653,828
--------------------------------------------------------------------------

The deposit will be mined by conventional open pit mining methods
using an initial fleet of 12 - 218 tonne haul trucks, two electric
hydraulic shovels, and various ancillary equipment to support the mining
operations.

The mine production daily rate, including waste, is estimated at 120,000
tonnes per day. The ore to waste ratio is estimated at 1.16 to 1. The
pit design includes an inter-ramp pit slope of 55 degrees.

Mining costs have been estimated at an average of $1.52 per tonne mined.
Fuel price assumption is based on $83 per barrel of oil. The average
annual fuel consumption is estimated at 28 million litres.

Mineral Processing

The plant design is a conventional cyanidation and carbon in pulp plant
with a nominal throughput capacity of 55,000 tonnes per day (20 M tonnes
per annum) based on 92% plant availability. Gold recovery is estimated at
84% based on an average head grade of 1.2g/t Au for design criteria.

Grind is estimated at P80 = 65 microns with an average leach time of 30
hours.

The design is based on numerous tests being conducted at various
laboratories. On-going optimization studies are currently underway.

In order to minimize the environmental impact of the Project, the use of
thickened tailings disposal technology has been selected. The actual
proposed plan is to dispose of the tailings over the former East Malartic
tailings area.

The mineral processing costs, including tailings operations and power,
are estimated at $4.55 /tonne milled.

Operating Costs

Total operating costs, including $0.60/tonne for general and
administration costs, are estimated at $8.43 per tonne milled or an
average of $369 per ounce before royalties.

The summary per year is outlined below, based on an average gold recovery
of 84%:

--------------------------------------------------------------------------
Year Tonnes Average Gold Cost/ounce Cost/ounce
Milled Grade Production Excluding Including
(000's) (g/t Au) (000's oz) Royalties Royalties
--------------------------------------------------------------------------
2011 20,075 1.02 556 311 325
--------------------------------------------------------------------------
2012 20,075 1.13 615 277 289
--------------------------------------------------------------------------
2013 20,075 1.00 544 319 331
--------------------------------------------------------------------------
2014 20,075 0.82 447 383 394
--------------------------------------------------------------------------
2015 20,075 0.74 403 436 448
--------------------------------------------------------------------------
2016 20,075 0.65 354 500 512
--------------------------------------------------------------------------
2017 20,075 0.76 414 428 440
--------------------------------------------------------------------------
2018 20,075 0.83 450 398 410
--------------------------------------------------------------------------
2019 20,075 0.90 486 374 385
--------------------------------------------------------------------------
2020 20,075 0.76 411 390 401
--------------------------------------------------------------------------
2021 20,075 0.76 413 390 402
--------------------------------------------------------------------------
2022 20,075 0.81 438 371 383
--------------------------------------------------------------------------
2023 20,075 0.87 474 347 359
--------------------------------------------------------------------------
2024 20,075 0.87 473 319 330
--------------------------------------------------------------------------
2025 6,647 0.39 70 530 542
--------------------------------------------------------------------------
Total 287,697 0.84 6,547 369 381
--------------------------------------------------------------------------

Rate of Return

Under the Base Case scenario at a gold price at $775 per ounce, the
Internal Rate of Return (IRR) is estimated at 22.2% before taxes and is
unleveraged.

The table below outlines sensitivities under various price scenarios:

-------------------------------------------------------------------------
Gold Price($) IRR(%) NPV at 5% discount(M $) NPV at 0% discount(M $)
-------------------------------------------------------------------------
650 13.0 394.5 904.7
-------------------------------------------------------------------------
775 22.2 952.3 1,710.8
-------------------------------------------------------------------------
900 30.5 1,464.1 2,516.9
-------------------------------------------------------------------------
1000 36.8 1,891.9 3,161.7
-------------------------------------------------------------------------

Financing

The Company has initiated discussions with financial
institutions with respect to funding the Project. The Company currently
has cash resources of approximately $160 M, and has invested $30 M as
progress payments on capital expenditures. In addition, the Company has
negotiated a $20 M unsecured financing with the Solidarity Fund QFL which
is expected to close in early April.

Path Forward

The Company is working to complete the feasibility study and the
Environmental Impact Assessment by the end of the third quarter/early
fourth quarter 2008. The infill drilling program at the Canadian Malartic
Property is scheduled for completion at the end of March 2008, with full
assay results being available in May. The measured and indicated resource
estimate on the entire deposit is to be released in July 2008.
Subsequently upon final pit design, a probable reserve calculation will
be completed for Definitive Feasibility purposes.

Sean Roosen President and CEO noted: "We have an aggressive plan to move
the Canadian Malartic Project to production by the end of 2010. During
the next six months we will be focused on completing the Definitive
Feasibility Study, optimizing the capital program, operating plans and
securing project financing."

Detailed Report

The entire Preliminary Assessment Study will be available as of April 1,
2008 at www.sedar.com and on the Company's corporate website
www.osisko.com.

Note: This Preliminary Assessment Study is conceptual in nature as it is
based on the inferred resource, which at this stage does not have a high
enough geostatistical level of confidence to provide the economic basis
for a production decision. The Company is completing its infill drilling
program and additional study, which if positive, may advance the Project
to the Definitive Feasibility level.

Qualified Person

The Preliminary Assessment Study was prepared by BBA Inc. under the
supervision of Mr. David Runnels, a registered professional engineer, an
independent Qualified Person under the standards set forth by National
Instrument 43-101. Mr. Luc Lessard, Vice-President Engineering and
Construction for Osisko and a registered professional engineer, is the
Company's designated Qualified Person for the purposes of the Study. Mr.
Runnels and Mr. Lessard have reviewed and approved the contents of this
press release.

Conference Call Osisko will host a conference call on Monday, March 31st at
10am EST where senior management, the Osisko Technical Group and BBA Inc.
representatives will discuss the Study and will be available to respond
to questions from analysts and investors. Those interested in
participating in the conference call should dial in at 416-850-9144
(Toronto local and international), or 1-866-400-3310 (North American toll
free). An operator will direct participants to the call.

Forward Looking Statements

Certain statements contained in this Press Release, including those
regarding production, costs, timing of permitting, construction or
production, future financial or operating performance and other
statements that express management's expectations or estimates of future
performance constitute "forward-looking statements". All statements,
other than statements of historical fact, are forward-looking statements.
Information concerning the interpretation of mineral resource and reserve
estimates and capital cost estimates may also be deemed as
forward-looking statements as such information constitutes a prediction
of what mineralization might be found to be present and how much capital
will be required if and when a project is actually developed. These
statements involve known and unknown risks, uncertainties and other
factors that may cause actual results or events to differ materially from
those anticipated in such forward-looking statements. These risks,
uncertainties and other factors include, but are not limited to: general
business and economic conditions; the supply and demand for, deliveries
of, and the level and volatility of prices of gold as well as petroleum
products; the timing of the receipt of regulatory and governmental
approvals for the Corporation's development project and other operations;
the availability of financing for the Corporation's development project
on reasonable terms; Osisko's estimation of its costs of production, its
expected production and its productivity levels, as well as those of its
competitors; power prices; the ability to procure equipment and operating
supplies in sufficient quantities and on a timely basis; the ability to
attract and retain skilled staff; engineering and construction timetables
and capital costs for Osisko's development project; market competition;
the accuracy of our resource estimate (including, with respect to size,
grade and recoverability) and the geological, operational and price
assumptions on which it is based; tax benefits and tax rates; the
Corporation's ongoing relations with its employees, its business partners
and joint venture partners and the community of Malartic.

These forward- looking statements involve risks and uncertainties
relating to, among other things, changes commodity and, particularly,
gold prices, access to skilled mining development and mill production
personnel, results of exploration and development activities, the
Corporation's limited experience with production and development stage
mining operations, uninsured risks, regulatory changes, defects in title,
availability of materials and equipment, timeliness of government
approvals, actual performance of facilities, equipment and processes
relative to specifications and expectations and unanticipated
environmental impacts on operations. These factors are discussed in
greater detail in the Corporation's most recent Annual Information Form
filed on SEDAR. Other assumptions are also more fully described in the
Study.

The Corporation cautions that the foregoing list of important factors is
not exhaustive. Investors and others who base themselves on the
Corporation's forward-looking statements should carefully consider the
above factors as well as the uncertainties they represent and the risk
they entail. The Corporation believes that the expectations reflected in
those forward-looking statements are reasonable, but no assurance can be
given that these expectations will prove to be correct and such
forward-looking statements included in this Press Release should not be
unduly relied upon. These statements speak only as of the date of this
Press Release. Actual results and developments are likely to differ, and
may differ materially, from those expressed or implied by the
forward-looking statements contained in this Press Release. Moreover,
these forward-looking statements may not be suitable for establishing
strategic priorities and objectives, future strategies or actions,
financial objectives and projections other than those mentioned above.

Contacts:
Osisko Exploration Ltd
John Burzynski
Vice-President Corporate Development
514-735-7131
www.osisko.com

Daniel Boase
Investor Relations
416-742-5600
Toll Free: 1-866-580-8891

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