Silver Wheaton Finalizes Amended Silver Purchase Agreement in Conjunction With Goldcorp's Sale of the San Dimas Mine

VANCOUVER, August 6, 2010 - Silver Wheaton Corp. ("Silver Wheaton" or the "Company") (TSX, NYSE:SLW)
is pleased to announce that, further to the Company's June 2, 2010 press
release, it has amended its silver purchase agreement relating to the San
Dimas mine ("San Dimas"). The agreement was amended pursuant to the August 6,
2010 completion of Goldcorp Inc.'s ("Goldcorp") sale of San Dimas to Primero
Mining Corp. ("Primero"), formerly known as Mala Noche Resources (see
Goldcorp and Primero press releases dated August 6, 2010). Key amendments to
the silver purchase agreement are as follows:

    - The term of the silver purchase agreement, which previously ended in
      2029, has been increased to life-of-mine;

    - During the first four years following closing, Primero will deliver
      to Silver Wheaton a per annum amount equal to the first 3.5 million
      ounces of payable silver produced at San Dimas and 50% of any excess,
      plus Silver Wheaton will receive an additional 1.5 million ounces of
      silver per annum to be delivered by Goldcorp;

    - Beginning in the fifth year after closing, Primero will deliver to
      Silver Wheaton a per annum amount equal to the first six million
      ounces of payable silver produced at San Dimas and 50% of any excess;

    - Goldcorp will continue to guarantee:

      i.  The delivery by Primero of all silver produced and owing to
          Silver Wheaton, until 2029; and,
      ii. A payment of US$0.50/oz for any shortfall below 215 million
          cumulative silver ounces delivered to Silver Wheaton by the
          end of 2031.

    - Primero has provided Silver Wheaton with a right of first refusal on
      any metal stream or similar transaction it enters into; and

    - Silver Wheaton has obtained an increased security package over the
      properties and assets of Primero.

Under the terms of the amended silver purchase agreement, Silver Wheaton
will continue to pay the lesser of US$4.04 (subject to an inflationary
adjustment) or the prevailing market price per ounce of silver delivered.

About San Dimas

San Dimas has been in continuous production for well over 100 years and
operates in the lowest cost quartile of gold-silver producers in the world.
Over the substantial mine life to date, the operating team at San Dimas has
demonstrated an exceptional track-record of converting resources into
reserves and the mine continues to exhibit excellent exploration upside.

Current exploration programs at San Dimas are focused on locating the
western extension of the Central Block region, where the majority of mining
currently takes place. These programs met with considerable success late in
2009, and continue into 2010, positioning the mine for a new phase of
long-term production growth.

About Silver Wheaton

Silver Wheaton is the largest silver streaming company in the world.
Forecast 2010 production, based upon its current agreements, is 22.2 million
ounces of silver and 20,000 ounces of gold, for total production of 23.5
million silver equivalent ounces. By 2013, annual production is anticipated
to increase significantly to approximately 38 million ounces of silver and
59,000 ounces of gold, for total production of over 40 million silver
equivalent ounces. This growth is driven by the Company's portfolio of
world-class assets, including silver streams on Goldcorp's Penasquito mine
and Barrick's Pascua-Lama project.

CAUTIONARY NOTE REGARDING FORWARD LOOKING-STATEMENTS

The information contained herein contains "forward-looking statements"
within the meaning of the United States Private Securities Litigation Reform
Act of 1995 and "forward-looking information" within the meaning of
applicable Canadian securities legislation. Forward-looking statements, which
are all statements other than statements of historical fact, include, but are
not limited to, statements with respect to the future price of silver and
gold, the estimation of mineral reserves and resources, the realization of
mineral reserve estimates, the timing and amount of estimated future
production, costs of production, reserve determination and reserve conversion
rates. Generally, these forward-looking statements can be identified by the
use of forward-looking terminology such as "plans", "expects" or "does not
expect", "is expected", "budget", "scheduled", "estimates", "forecasts",
"intends", "anticipates" or "does not anticipate", or "believes", or
variations of such words and phrases or statements that certain actions,
events or results "may", "could", "would", "might" or "will be taken",
"occur" or "be achieved". Forward-looking statements are subject to known and
unknown risks, uncertainties and other factors that may cause the actual
results, level of activity, performance or achievements of Silver Wheaton to
be materially different from those expressed or implied by such
forward-looking statements, including but not limited to: fluctuations in the
price of silver and gold; the absence of control over mining operations from
which Silver Wheaton purchases silver or gold and risks related to these
mining operations including risks related to fluctuations in the price of the
primary commodities mined at such operations, actual results of mining and
exploration activities, economic and political risks of the jurisdictions in
which the mining operations are located and changes in project parameters as
plans continue to be refined; and differences in the interpretation or
application of tax laws and regulations; as well as those factors discussed
in the section entitled "Description of the Business - Risk Factors" in
Silver Wheaton's Annual Information Form available on SEDAR at www.sedar.com
and in Silver Wheaton's Form 40-F on file with the U.S. Securities and
Exchange Commission in Washington, D.C. Forward-looking statements are based
on assumptions management believes to be reasonable, including but not
limited to: the continued operation of the mining operations from which
Silver Wheaton purchases silver or gold, no material adverse change in the
market price of commodities, that the mining operations will operate and the
mining projects will be completed in accordance with their public statements
and achieve their stated production outcomes, and such other assumptions and
factors as set out herein. Although Silver Wheaton has attempted to identify
important factors that could cause actual results to differ materially from
those contained in forward-looking statements, there may be other factors
that cause results not to be as anticipated, estimated or intended. There can
be no assurance that forward-looking statements will prove to be accurate.
Accordingly, readers should not place undue reliance on forward-looking
statements. Silver Wheaton does not undertake to update any forward-looking
statements that are included or incorporated by reference herein, except in
accordance with applicable securities laws.

For further information: For further information: Brad Kopp, Vice
President, Investor Relations, Silver Wheaton Corp., Tel: +1-800-380-8687,
Email: info@silverwheaton.com, Website: www.silverwheaton.com

For further information: For further information: Brad Kopp, Vice President, Investor Relations, Silver Wheaton Corp., Tel: +1-800-380-8687, Email: info at silverwheaton.com