Silver Wheaton Corp.: Exhibit 99.1 - Filed by newsfilecorp.com

THE BANK OF NOVA SCOTIA
as Co-Lead Arranger, Joint Bookrunner and Administrative Agent

CANADIAN IMPERIAL BANK OF COMMERCE,
ROYAL BANK OF CANADA AND THE TORONTO-DOMINION BANK
as Co-Documentation Agents

BANK OF TOKYO-MITSUBISHI UFJ (CANADA), EXPORT DEVELOPMENT CANADA AND HSBC BANK CANADA
as Senior Managers

THE BANK OF NOVA SCOTIA, BANK OF MONTREAL, CANADIAN IMPERIAL BANK OF COMMERCE, ROYAL BANK OF CANADA, THE TORONTO-DOMINION BANK, BANK OF TOKYO-MITSUBISHI UFJ (CANADA), EXPORT DEVELOPMENT CANADA, HSBC BANK CANADA, MIZUHO BANK, LTD., NATIONAL BANK OF CANADA AND BANK OF AMERICA, N.A., CANADA BRANCH
as Lenders

FIRST AMENDING AGREEMENT TO
AMENDED AND RESTATED REVOLVING TERM FACILITY CREDIT AGREEMENT

THE BANK OF NOVA SCOTIA, a Canadian chartered bank

(herein, in its capacity as administrative agent for the Lenders, called the “Administrative Agent”)

- and -

SILVER WHEATON CORP., a corporation continued under the laws of the Province of Ontario

(herein called the “Borrower”)

- and -

THE SEVERAL LENDERS FROM TIME TO TIME PARTY TO THE CREDIT AGREEMENT (herein and therein in their capacities as lenders to the Borrower, collectively called the “Lenders” and individually called a “Lender”)

WHEREAS the Borrower, the Lenders and the Administrative Agent entered into an amended and restated credit agreement dated as of February 27, 2015 in connection with a certain credit facility in favour of the Borrower (the “Credit Agreement”);

AND WHEREAS the Borrower, the Lenders and the Administrative Agent hereto wish to amend certain provisions of the Credit Agreement;

NOW THEREFORE THIS AGREEMENT WITNESSES that, in consideration of the mutual covenants and agreements contained herein, the parties covenant and agree as follows:

All capitalized terms which are used herein without being specifically defined herein shall have the meanings ascribed thereto in the Credit Agreement.

Subject to the terms and conditions herein contained, the Credit Agreement is hereby amended to the extent necessary to give effect to the provisions of this agreement and to incorporate the provisions of this agreement into the Credit Agreement.

““Interest Coverage Ratio” means, for any particular period, the ratio of Rolling EBITDA for such period to the Rolling Interest Expenses for such period; provided that, for purposes of calculating this ratio, in the definition of “Rolling Interest Expenses” (and including in the definition of “Rolling Permitted Acquisition Interest Expenses”): (i) references to “Interest Expenses” shall only include such expenses payable in cash and (ii) references to “consolidated capitalized interest expenses” shall only include capitalized interest expenses payable in cash.”

To induce the Lenders and the Administrative Agent to enter into this agreement, the Borrower hereby represents and warrants to the Lenders and the Administrative Agent that the representations and warranties of the Borrower which are contained in Section 10.1 of the Credit Agreement, as hereby amended, are true and correct on the date hereof as if made on the date hereof.

This agreement shall not become effective until the following conditions precedent are fulfilled:

The Borrower represents and warrants to and in favour of the Administrative Agent and the Lenders that no Default has occurred and is continuing as at the date this agreement becomes effective and no Default would arise immediately thereafter.

On and after the date of this agreement, each reference in the Credit Agreement to “this agreement”, “hereunder”, “hereof”, or words of like import referring to the Credit Agreement, and each reference in any related document to the “Credit Agreement”, “thereunder”, “thereof”, or words of like import referring to the Credit Agreement, shall mean and be a reference to the Credit Agreement as amended hereby. The Credit Agreement, as amended hereby, is and shall continue to be in full force and effect and is hereby in all respects ratified and confirmed.

This agreement shall be governed by and construed in accordance with the laws of the Province of Ontario.

This agreement shall enure to the benefit of and shall be binding upon the parties hereto and their respective successors and permitted assigns.

If any provision of this agreement is inconsistent or conflicts with any provision of the Credit Agreement, the relevant provision of this agreement shall prevail and be paramount. This agreement shall not create any novation.

This agreement shall not limit, impair or constitute a waiver of the rights, powers or remedies available to the Administrative Agent or the Lenders under the Credit Agreement or any other Credit Document.

The Borrower shall do, execute and deliver or shall cause to be done, executed and delivered all such further acts, documents and things as the Administrative Agent may reasonably request for the purpose of giving effect to this agreement and to each and every provision hereof.

This agreement may be executed in one or more counterparts, each of which shall be deemed to be an original and all of which taken together shall be deemed to constitute one and the same instrument.

IN WITNESS WHEREOF, the parties hereto have executed and delivered this agreement on the date first above written.

SILVER WHEATON CORP.


By:	/s/ Curt D. Bernardi
	Name: Curt D. Bernardi
	Title: Senior Vice President, Legal and
	Corporate Secretary


By:	/s/ Haytham Hodaly
	Name: Haytham Hodaly
	Title: Senior Vice President, Corporate
	Development

THE BANK OF NOVA SCOTIA, as
Administrative Agent


By:	/s/ Clement Yu
	Name: Clement Yu
	Title: Director


	/s/ Alastair Borthwick
	Name: Alastair Borthwick
	Title: Managing Director

THE BANK OF NOVA SCOTIA, as Lender


By:	/s/ Kurt R. Foellmer
	Name: Kurt R. Foellmer
	Title: Director


By:	/s/ Stephen MacNeil
	Name: Stephen MacNeil
	Title: Associate Director

CANADIAN IMPERIAL BANK OF
COMMERCE, as Lender


By:	/s/ Peter Rawlins
	Name: Peter Rawlins
	Title: Executive Director


By:	/s/ Jens Paterson
	Name: Jens Paterson
	Title: Executive Director

ROYAL BANK OF CANADA, as Lender


By:	/s/ Stam Fountoulakis
	Name: Stam Fountoulakis
	Title: Authorized Signatory


By:
	Name:
	Title:

THE TORONTO-DOMINION BANK, as
Lender


By:	/s/ Matthew Hendel
	Name: Matthew Hendel
	Title: Managing Director


By:	/s/ Ben Montgomery
	Name: Ben Montgomery
	Title: Director

BANK OF TOKYO-MITSUBISHI UFJ
(CANADA), as Lender


By:	/s/ Michael Quinn
	Name: Michael Quinn
	Title: Director


By:
	Name:
	Title:

EXPORT DEVELOPMENT CANADA, as
Lender


By:	/s/ Victor Samuel
	Name: Victor Samuel
	Title: Asset Manager


By:	/s/ Hivda Morissette
	Name: Hivda Morissette
	Title: Asset Manager

HSBC BANK CANADA, as Lender


By:	/s/ Mike Wells
	Name: Mike Wells
	Title: Vice President Global Banking


By:	/s/ Dieter Stefely
	Name: Dieter Stefely
	Title: Director, Banking

MIZUHO BANK, LTD., as Lender


By:	/s/ Rob MacKinnon
	Name: Rob MacKinnon
	Title: Senior Vice President Canada Branch


By:
	Name:
	Title:

NATIONAL BANK OF CANADA, as
Lender


By:	/s/ Roch Ledoux
	Name: Roch Ledoux
	Title: Directeur - Director


By:	/s/ Bruno Levesque
	Name: Bruno Levesque
	Title: Directeur - Director

BANK OF AMERICA, N.A., CANADA
BRANCH, as Lender


By:	/s/ Marc Ahlers
	Name: Marc Ahlers
	Title: Vice President


By:
	Name:
	Title:

The undersigned, each being a guarantor of the Borrower’s Obligations under, inter alia, the Credit Agreement, hereby acknowledge, agree to and consent to the foregoing amendments to the Credit Agreement and hereby confirm their obligations under their respective Guarantee.

SILVER WHEATON (CAYMANS) LTD.


By:	/s/ Nik Tatarkin
Name:	Nik Tatarkin
Title:	President

By:
Name:
Title:


SILVER WHEATON LUXEMBOURG
SARL


By:	/s/ Nik Tatarkin
Name:	Nik Tatarkin
Title:	Manager A

By:
Name:
Title:

WHEATON PRECIOUS METALS
(CAYMAN) CO.


By:	/s/ Nik Tatarkin
Name:	Nik Tatarkin
Title:	Director

By:
Name:
Title:

BANK OF MONTREAL, as Lender


By:	/s/ Jerry Kaye
	Name: Jerry Kaye
	Title: Director


By:
	Name:
	Title: