Silver Wheaton Acquires Life of Mine Silver Production From Mercator Minerals

Market Wire, March, 2008

Silver Wheaton Corp. ("Silver Wheaton") (TSX: SLW)(NYSE: SLW) is pleased to announce that it has agreed to purchase all of the silver produced by Mercator Minerals Ltd. ("Mercator") (TSX: ML), at its copper-molybdenum-silver Mineral Park Mine in Arizona.

Upon the successful close of the transaction, Silver Wheaton will pay Mercator an upfront cash payment of US$42 million in order to acquire the silver produced by the Mineral Park Mine over its entire mine life, for the lesser of US$3.90 (subject to a one percent annual adjustment beginning three years after a minimum production level has been met) and the prevailing market price per ounce of silver. Payment for the transaction will be drawn from existing credit facilities and Silver Wheaton is not required to pay any further capital expenditures for the life of the mine.

The Mineral Park Mine currently produces copper from SX/EW leach operations, but construction is well underway on a flotation operation that will produce copper-silver and molybdenum concentrates. Mercator expects that concentrate production will commence before July 2008 from a 25,000 tons per day operation, with production increasing to 50,000 tons per day approximately nine months later. All permits for the expansion are in place and the expected mine life is 25 years. Payable silver production is expected to average approximately 600,000 ounces per annum over the first 21 years of operations and the ore body is considered to have excellent exploration potential.

Mercator will provide a completion guarantee to Silver Wheaton, specifying a minimum production level by a certain date.

"Silver Wheaton continues to deliver on its promise of accretive acquisitions of silver streams," said Peter Barnes, President and Chief Executive Officer of Silver Wheaton. "Mercator has assembled an excellent operating team and we are proud to be partnered with another successful US based copper producer from which we expect to begin receiving delivery of silver this year. This is another example of how Silver Wheaton can work with our operating partners to help them grow."

Mr. Randy V.J. Smallwood, P.Eng., Silver Wheaton's Executive Vice President of Corporate Development, who is a "qualified person" as such term is defined under National Instrument 43-101, has reviewed and approved the contents of this news release. Production rates, reserves and resources are as reported by Mercator in a technical report dated December 29, 2006.

Silver Wheaton is the largest public mining company with 100% of its operating revenue from silver production. Silver Wheaton's 2008 silver sales are expected to approximate 15 million ounces, increasing to 25 million ounces in 2010. Silver Wheaton is unhedged and well positioned for further growth.

Mineral Park silver reserves and resources are as follows:

Mineral Park Mine Reserves and Resources(1,3,6,7)

                                                        Contained
                           Tonnage     Silver Grade        Silver
                           -------     ------------     ---------
Category                  (million       (grams per      (million
--------                    tonnes)           tonne)       ounces)

Reserves(2)
----------
Proven                       315.9             2.85          29.0
Probable                      81.3             2.45           6.4
                           -------     ------------     ---------
Proven   Probable            397.2             2.77          35.4
                           -------     ------------     ---------
                           -------     ------------     ---------

Resources(4,5)
-------------
Measured                     290.5             2.59          24.2
Indicated                    154.2             2.64          13.1
                           -------     ------------     ---------
Measured   Indicated         444.6             2.61          37.3
Inferred                     198.4             2.33          14.9
                           -------     ------------     ---------
                           -------     ------------     ---------

Notes:

1. Mineral Reserves and Mineral Resources for Mineral Park have been
   calculated as of December 29, 2006 in accordance with the standards
   of the Canadian Institute of Mining, Metallurgy and Petroleum and
   National Instrument 43-101.

2. The above Mineral Reserves do not include the low grade SX/EW
   leachable Mineral Reserves of 82.5 million tonnes, which only
   produce copper to the credit of Mercator.

3. Mineral Reserves and Mineral Resources are estimated using
   appropriate metallurgical recovery rates in the calculation of
   copper equivalent cut off grades.

4. Measured and Indicated Mineral Resources are inclusive of Mineral
   Reserves.

5. Mineral Resources are reported using a 0.3% copper equivalent cut
   off grade.

6. Mineral Resources which are not Mineral Reserves do not have
   demonstrated economic viability.

7. As reported by Mercator in their technical report dated December 29,
   2006. The report can be found at  www.sedar.com .