Brett Reports Osisko Formally Launches Friendly Offer to Acquire Brett

Brett Resources Inc. (TSX VENTURE:BBR) (FRANKFURT:A4N) is pleased to announce
that Osisko Mining Corporation ("Osisko") (TSX:OSK)(FRANKFURT:EWX) announced
today that it has mailed shareholders of Brett Resources Inc. ("Brett") and
filed with the Canadian securities regulatory authorities and the U.S.
Securities and Exchange Commission, the offer and take-over bid circular
(collectively the "Offer Documents"), formally commencing Osisko's friendly
offer to acquire (the "Offer") all of the outstanding common shares of Brett on
the basis of 0.34 of an Osisko common share and $0.0001 in cash for each common
share of Brett. As previously announced, Osisko and Brett entered into a support
agreement ("Support Agreement") on March 21, 2010 providing for the terms of the
Offer and the agreement by the board of directors of Brett to recommend that
Shareholders accept the Offer. The consideration under the Offer represents a
premium of 52.5% using the 20-day volume weighted average prices of Osisko and
Brett quoted on the Toronto Stock Exchange and TSX Venture Exchange,
respectively, for the 20 trading day period ending March 16, 2010.


In addition, Brett has prepared a Directors Circular in accordance with Canadian
securities law requirements, which confirms that the board of directors of Brett
has unanimously approved the Offer, has determined it is fair and is in the best
interests of Brett and the Shareholders, and that the board of directors of
Brett unanimously recommends that Shareholders accept the Offer and tender their
Brett common shares to the Offer. The Directors Circular was mailed concurrently
with the Offer Documents.


Full details of the Offer are contained in the Offer Documents and the Directors
Circular. Shareholders are encouraged to read the documents and to consider the
important information contained therein. Copies of the Offer Documents and
Directors Circular along with other relevant documents are available
electronically at www.sedar.com. The Offer is open for acceptance until 5:00
p.m. (Toronto time) on May 19, 2010.


Patrick Soares, President and CEO of Brett commented, "Shareholders and other
stakeholders who expressed satisfaction with the acknowledged expertise and
financial strength Osisko brings to the development of Hammond Reef and the
possible accelerated development path directed by Osisko's experienced team,
which has a proven record of mine permitting and development."


Osisko has retained Kingsdale Shareholder Services Inc. to act as both its
information agent and depositary in connection with the Offer.


About Osisko Mining Corporation

Osisko Mining Corporation is currently developing the Canadian Malartic gold
deposit and evaluating adjacent areas for a large-scale open pit, bulk-tonnage
mining operation. The Canadian Malartic deposit currently represents one of the
biggest gold reserves in Canada for a single deposit, and is still growing
through ongoing drilling on new mineralized zones. Current reserves for the
Canadian Malartic property (including the adjacent South Barnat deposit) are
8.97 million ounces, plus a global measured and indicated resource of 2.23
million ounces and an inferred resource of 0.47 million ounces (see press
release of February 10, 2010).


About Brett Resources Inc.

Brett Resources Inc. is a Canadian minerals exploration company whose primary
mandate is the discovery, acquisition, and development of precious metals
systems, with particular expertise in Canada and Latin America. Since 2006
Brett's primary focus has been the 100 percent owned Hammond Reef Gold Deposit
in Ontario where an inferred resource of 6.70 million ounces of gold, 259.4
million tonnes at a grade of 0.8 grams per tonne utilizing a 0.3 gram per tonne
gold cut-off has been outlined.


FOR FURTHER INFORMATION

Shareholders should contact the Information Agent, Kingsdale Shareholder
Services Inc. at 1-877-659-1824, for assistance in accepting the Offer and in
depositing their Brett common shares. Brett common shares should be deposited
under the Offer with the depositary, being Kingsdale Shareholder Services Inc.
Shareholders whose common shares are registered in the name of an investment
advisor, stock broker, bank, trust company or other nominee should immediately
contact that nominee for assistance if they wish to accept the Offer in order to
take the necessary steps to be able to deposit such common shares under the
Offer.


This press release does not constitute an offer to buy or an invitation to sell,
or the solicitation of an offer to buy or invitation to sell, any of the
securities of Osisko or Brett. Such an offer may only be made pursuant to an
offer and take-over bid circular filed with the securities regulatory
authorities in Canada.


Osisko has also filed with the U.S. Securities and Exchange Commission ("SEC") a
Registration Statement, which includes the offer and take-over bid circular and
prospectus relating to its offer to Brett shareholders. OSISKO URGES INVESTORS
AND SECURITY HOLDERS TO READ THE REGISTRATION STATEMENT, THE OFFER AND TAKE-OVER
BID CIRCULAR AND ANY OTHER RELEVANT DOCUMENTS TO BE FILED WITH THE SEC AND
CANADIAN SECURITIES REGULATORY AUTHORITIES, BECAUSE THEY CONTAIN IMPORTANT
INFORMATION. Investors may obtain a free copy of the offer and take-over bid
circular and other documents filed by Osisko with the Canadian securities
regulators at www.sedar.com and with the SEC at the SEC's website at
www.sec.gov. The offer and take-over bid circular and other documents may also
be obtained for free, from Osisko's website (www.osisko.com) or by directing a
request to Osisko's investor relations department by telephone at
1-888-674-7563, fax [phone] or e-mail [e-mail] or by contacting the
Information Agent, Kingsdale Shareholder Services Inc., toll free at
1-877-659-1824.


Forward-Looking Information

Certain statements contained in this press release may be deemed
"forward-looking statements". All statements in this release, other than
statements of historical fact, that address events or developments that Osisko
and Brett expect to occur, are forward looking statements. Forward looking
statements are statements that are not historical facts and are generally, but
not always, identified by the words "expects", "plans", "anticipates",
"believes", "intends", "estimates", "projects", "potential", "scheduled" and
similar expressions, or that events or conditions "will", "would", "may",
"could" or "should" occur. Although Osisko and Brett believe the expectations
expressed in such forward-looking statements are based on reasonable
assumptions, including, without limitation that all technical, economical and
financial conditions will be met in order to put the Canadian Malartic Project
and the Hammond Reef Gold Project into commercial production, such statements
are not guarantees of future performance and actual results may differ
materially from those in forward looking statements. Factors that could cause
the actual results to differ materially from those in forward-looking statements
include gold prices, access to skilled consultants, mining development and mill
production personnel, results of exploration and development activities, Osisko
and Brett's limited experience with production and development stage mining
operations, uninsured risks, regulatory changes, defects in title, availability
of personnel, materials and equipment, timeliness of government approvals,
actual performance of facilities, equipment and processes relative to
specifications and expectations, unanticipated environmental impacts on
operations market prices, continued availability of capital and financing and
general economic, market or business conditions. These factors are discussed in
greater detail in Osisko and Brett's most recent Annual Information Forms, both
of which are filed on SEDAR, which also provide additional general assumptions
in connection with these statements. Osisko and Brett caution that the foregoing
list of important factors is not exhaustive. Investors and others who base
themselves on the forward-looking statements contained herein should carefully
consider the above factors as well as the uncertainties they represent and the
risk they entail. Osisko and Brett believe 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.