F-10/A

As filed with the Securities and Exchange Commission on May 16, 2014

Registration No. 333-193876

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

AMENDMENT NO. 6 TO

FORM F-10

REGISTRATION STATEMENT UNDER
THE SECURITIES ACT OF 1933

HudBay Minerals Inc.

(Exact Name of Registrant as Specified in its Charter)

Canada
(Province or Other Jurisdiction of Incorporation or Organization)

1000
(Primary Standard Industrial Classification Code Number)

98-0485558
(I.R.S. Employee Identification No.)

25 York Street, Suite 800
Toronto, Ontario
M5J 2V5, Canada
Telephone:  (416) 362-8181
(Address, including postal code, and telephone number, including area code, of Registrant’s principal executive offices)

Corporation Service Company
1180 Ave of the Americas, Suite 210
New York, NY 10036
Telephone:  (212) 299-5600
(Name, Address (Including Zip Code) and Telephone Number (Including Area Code) of Agent for Service in the United States)

Copies to:

Patrick Donnelly, Esq.	Mark L. Mandel, Esq.	Kari MacKay, Esq.
HudBay Minerals Inc.	Milbank, Tweed, Hadley & McCloy LLP	Goodmans LLP
25 York Street, Suite 800	One Chase Manhattan Plaza	Bay Adelaide Centre
Toronto, Ontario	New York, NY 10005-1413	333 Bay Street, Suite 3400
M5J 2V5, Canada	(212) 530-5000	Toronto, ON M5H 2S7
(416) 362-8181		(416) 979-2211

Approximate date of commencement of proposed sale of the securities to the public:  as soon as practicable after this registration statement becomes effective.

Province of Ontario, Canada
(Principal Jurisdiction Regulating this Form F-10 Offering)

It is proposed that this filing shall become effective (check appropriate box):

A.xupon filing with the Commission, pursuant to Rule 467(a) (if in connection with an offering being made contemporaneously in the United States and Canada).

B.oat some future date (check appropriate box below):

1.oPursuant to Rule 467(b) on (         ) at (         ) (designate a time not sooner than seven calendar days after filing).

2.oPursuant to Rule 467(b) on (         ) at (         ) (designate a time seven calendar days or sooner after filing) because the securities regulatory authority in the review jurisdiction has issued a receipt or notification of clearance on (         ).

3.oPursuant to Rule 467(b) as soon as practicable after notification of the Commission by the registrant or the Canadian securities regulatory authority of the review jurisdiction that a receipt or notification of clearance has been issued with respect hereto.

4.oAfter the filing of the next amendment to this form (if preliminary material is being filed).

If any of the securities being registered on this Form F-10 are to be offered on a delayed or continuous basis pursuant to the home jurisdiction’s shelf prospectus offering procedures, check the following box.  o

CALCULATION OF REGISTRATION FEE

Title of Each Class of Securities to be Registered	Amount to be Registered(1)	Proposed Maximum Offering Price Per Unit		Proposed Maximum Aggregate Offering Price(2)		Amount of Registration Fee(3)
Common Shares, without par value	41,921,758	$	1.80	$	238,887,478.07	$	30,768.71

(1)Represents the maximum number of HudBay Minerals Inc. (“Hudbay”) common shares, without par value (“Hudbay shares”), estimated to be issuable upon consummation of the exchange offer (the “Offer”) for all of the issued and outstanding common shares (the “Common Shares”) of Augusta Resource Corporation (“Augusta”), assuming the exercise of all the in-the-money convertible securities of Augusta, other than any Common Shares owned directly or indirectly by Hudbay and its affiliates, which equals (a)(i) 156,143,531, the number of Common Shares reported as outstanding on a fully diluted basis (assuming the exercise of all the in-the-money convertible securities of Augusta) as of November 13, 2013 in the Management’s Discussion and Analysis for the Third Quarter Ended September 30, 2013 and after giving effect to the 3.3 million Common Share purchase warrants Augusta issued in December 2013, minus (ii) 23,058,585, the number of Common Shares owned directly or indirectly by Hudbay and its affiliates as of February 5, 2014, multiplied by (b) 0.315, which represents the number of Hudbay Shares to be exchanged for each Common Share pursuant to the transactions described herein.

(2)Estimated solely for the purpose of calculating the registration fee in accordance with General Instruction II.H to Form F-10. The proposed maximum aggregate offering price is equal to the product of (i) US$1.795, which is the average of high and low sale prices of the Common Shares as reported on the NYSE MKT on February 5, 2014, and (ii) 133,084,946 Common Shares in the aggregate that may be received by Hudbay or cancelled in the transaction described herein.

(3)Previously paid.

If, as a result of stock splits, stock dividends or similar transactions, the number of securities purported to be registered on this Registration Statement changes, the provisions of Rule 416 under the Securities Act of 1933, as amended, shall apply to this Registration Statement.

PART I

INFORMATION REQUIRED TO BE DELIVERED

TO OFFEREES OR PURCHASERS

Item 1.Home Jurisdiction Document

This Amendment No. 6 (“Amendment No. 6”) amends and supplements the registration statement on Form F-10 filed on February 11, 2014 (as amended, the “Registration Statement”) by HudBay Minerals Inc., a corporation existing under the laws of Canada (“Hudbay” or the “Registrant”).

The Registration Statement relates to the offer to purchase (the “Offer”) by Hudbay for all of the issued and outstanding common shares (the “Common Shares”) of Augusta Resource Corporation, a corporation existing under the laws of Canada (“Augusta”), other than any Common Shares held directly or indirectly by Hudbay and its affiliates, including any Common Shares that may become issued and outstanding upon the exercise, exchange or conversion of any options or any other rights to acquire Common Shares after the date of the Offer but prior to the expiry time of the Offer, together with the associated rights issued under Augusta’s shareholder rights plan, for consideration per Common Share of 0.315 of a common share of Hudbay.

The Offer is subject to the terms and conditions set forth in Hudbay’s Offer and Circular dated February 10, 2014 (as previously amended, the “Original Offer and Circular”) and related Letter of Transmittal and Notice of Guaranteed Delivery, each as previously amended, copies of which are attached to the Registration Statement as Exhibits 1.1, 1.2, and 1.3, respectively, and the terms and conditions set forth in the Notice of Variation and Extension, dated May 16, 2014 (“Notice of Variation and Extension”).

The information set forth in the Original Offer and Circular, the Letter of Transmittal and the Notice of Guaranteed Delivery, including all schedules, exhibits and annexes thereto, is hereby expressly incorporated herein by reference in response to all items of information required to be included in, or covered by, a registration statement on Form F-10, and is supplemented by the information specifically provided herein, including in the Notice of Variation and Extension, a copy of which is attached to this Amendment No. 6 as Exhibit 4.17.

Except as specifically provided herein, this Amendment No. 6 does not modify any of the information previously reported in the Registration Statement.

Item 2.Additional Information.

See the financial statements included or incorporated by reference in the Original Offer and Circular and the Notice of Change.

Item 3.Informational Legends.

See the outside front cover page and the introduction of the Original Offer and Circular.

Item 4.Incorporation of Certain Information by Reference.

See “Circular - Documents Incorporated by Reference” in the Original Offer and Circular.

Item 5.List of Documents filed with the SEC.

The following documents have been filed with the U.S. Securities and Exchange Commission (the “Commission”) as part of the Registration Statement: (i) the Original Offer and Circular, Letter of Transmittal,  Notice of Guaranteed Delivery and Notice of Variation and Extension; (ii) press releases related to the Offer; (iii) investor relations presentations; (iv) the transcript of a conference call related to the Offer; (v) a newspaper advertisement related to the Offer; (vi) an early warning report filed under National Instrument 62-103 related to the Offer; (vii) material change reports related to the Offer; (viii) press releases related to Hudbay’s financial results; (ix) management’s discussion and analysis and audited financial statements for the year ended December 31, 2013; (x) management’s discussion and analysis and unaudited financial statements for the three months ended March 31, 2014; (xi) the documents listed in the Original Offer and Circular as incorporated by reference herein; and (xii) consents of auditors, counsel and qualified persons.

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PART II

INFORMATION NOT REQUIRED TO BE DELIVERED
TO OFFEREES OR PURCHASERS.

Indemnification of Officers and Directors

The by-laws of Hudbay provide that, subject to the relevant provisions of the Canada Business Corporations Act, Hudbay shall indemnify a director or officer of Hudbay, a former director or officer of Hudbay, or another individual who acts or acted at Hudbay’s request as a director or officer, or an individual acting in a similar capacity, of another entity, against all costs, charges and expenses, including an amount paid to settle an action or satisfy a judgment, reasonably incurred by the individual in respect of any civil, criminal, administrative, investigative or other proceeding in which the individual is involved because of that association with Hudbay or such other entity if (i) the individual acted honestly and in good faith with a view to the best interests of Hudbay or, as the case may be, to the best interests of the other entity for which the individual acted as a director or officer or in a similar capacity at Hudbay’s request; and (ii) in the case of a criminal or administrative action or proceeding that is enforced by a monetary penalty, the individual has reasonable grounds for believing that the individual’s conduct was lawful.

Hudbay also maintains insurance for the benefit of its directors and officers against liability in their respective capacities as directors and officers.  The directors and officers are not required to pay any premium in respect of the insurance.  The policy contains standard industry exclusions.

Insofar as indemnification for liabilities arising under the United States Securities Act of 1933 may be permitted to directors, officers or persons controlling the Registrant pursuant to the foregoing provisions, the Registrant has been informed that in the opinion of the U.S. Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is therefore unenforceable.

EXHIBITS TO FORM F-10

The exhibits to this Registration Statement are listed in the exhibit index, which appears elsewhere herein.

PART III

UNDERTAKING AND CONSENT TO SERVICE OF PROCESS

Item 1. Undertaking.

The Registrant undertakes to make available, in person or by telephone, representatives to respond to inquiries made by the Commission staff, and to furnish promptly, when requested to do so by the Commission staff, information relating to the securities registered pursuant to this Form F-10 or to transactions in said securities.

Item 2. Consent to Service of Process.

Concurrently with the filing of the initial Registration Statement, the Registrant filed with the Commission a written irrevocable consent and power of attorney on Form F-X.

Any change to the name or address of the agent for service of the Registrant shall be communicated promptly to the Commission by amendment to the applicable Form F-X referencing the file number of the Registration Statement.

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SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form F-10 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Toronto, Province of Ontario, Canada, on this 16th day of May, 2014.

HUDBAY MINERALS INC.
By:	/s/Patrick Donnelly
	Name:	Patrick Donnelly
	Title:	Vice President, Legal and Corporate Secretary

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

Signature	Title	Date
*	President, Chief Executive Officer	May 16, 2014
David A. Garofalo	(Principal Executive Officer) and Director
*	Senior Vice President and Chief Financial Officer	May 16, 2014
David S. Bryson	(Principal Financial Officer)
*
G. Wesley Voorheis	Chairman and Director	May 16, 2014
*
Tom A. Goodman	Director	May 16, 2014
*
Alan R. Hibben	Director	May 16, 2014
*
W. Warren Holmes	Director	May 16, 2014
*
John L. Knowles	Director	May 16, 2014
*
Alan J. Lenczner	Director	May 16, 2014
*
Kenneth G. Stowe	Director	May 16, 2014
*
Sarah B. Kavanagh	Director	May 16, 2014
*
Igor Gonzales	Director	May 16, 2014

*By:	/s/Patrick Donnelly
	Patrick Donnelly
	Attorney-in-Fact

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AUTHORIZED REPRESENTATIVE

Pursuant to the requirements of Section 6(a) of the Securities Act, the undersigned has signed this registration statement, solely in the capacity of the duly authorized representative of the Registrant in the United States, in the City of Newark, State of Delaware, USA on this 16th day of May, 2014.

Donald J. Puglisi
(Authorized U.S. Representative)
by	/s/Donald J. Puglisi
	Name: Donald J. Puglisi
	Title: Managing Director
	Puglisi & Associates

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INDEX TO EXHIBITS

Exhibits to Form F-10

Exhibit No.
1.1**	Offer and Circular dated February 10, 2014.
1.2**	Form of Letter of Transmittal.
1.3**	Form of Notice of Guaranteed Delivery.
1.4**	Press Release dated February 10, 2014 (incorporated by reference to Hudbay’s filing pursuant to Rule 425 on February 10, 2014).
1.5**	Investor Relations Presentation related to the offer dated February 10, 2014 (incorporated by reference to Hudbay’s filing pursuant to Rule 425 on February 10, 2014).
1.6**	Investor Relations Presentation related to Constancia Project dated February 2014 (incorporated by reference to Hudbay’s filing pursuant to Rule 425 on February 10, 2014).
1.7**	Early warning report under National Instrument 62-103 (incorporated by reference to Hudbay’s Form 6-K filed February 10, 2014).
1.8**	Conference call transcript dated February 10, 2014 (incorporated by reference to Hudbay’s filing pursuant to Rule 425 on February 10, 2014).
1.9**	Newspaper Advertisement dated February 11, 2014.
4.1**	The Annual Information Form of HudBay Minerals Inc. for the year ended December 31, 2012 (incorporated by reference to Exhibit 99.1 to Hudbay’s Form 40-F (Commission File No. 001-34244) filed with the Commission on March 28, 2013 (the “Form 40-F”)).
4.2**	The annual audited consolidated financial statements of HudBay Minerals Inc. for the years ended December 31, 2012 and 2011 and notes and the auditor’s report in respect thereof, and the management’s discussion and analysis of HudBay Minerals Inc. for the financial years ended December 31, 2012 and 2011 (incorporated by reference to Exhibits 99.2 and 99.3 to the Form 40-F).
4.3**	The notice of annual and special meeting of shareholders and management information circular dated April 5, 2013 in respect of the annual and special meeting of shareholders held on May 10, 2013 (incorporated by reference to Exhibit 99.2 to Hudbay’s Form 6-K (Commission File No. 001-34244), furnished to the Commission on April 10, 2013).
4.4**	The material change report of HudBay Minerals Inc., dated June 20, 2013, in respect of the announcement of the offering of an additional US$150 million aggregate principal amount of the Company’s 9.50% senior unsecured notes and the closing of such offering (incorporated by reference to Exhibit 99.1 to Hudbay’s Form 6-K (Commission File No. 001-34244), furnished to the Commission on June 21, 2013).
4.5**	The unaudited condensed consolidated interim financial statements for the three and nine months ended September 30, 2013 and notes related thereto, together with the credit supporter disclosure filed concurrently therewith, and the management’s discussion and analysis for the three and nine months ended September 30, 2013 (incorporated by reference to Exhibits 99.1 and 99.2 to Hudbay’s Form 6-K (Commission File No. 001-34244), furnished to the Commission on November 12, 2013).
4.6**	The material change report of HudBay Minerals Inc., dated November 13, 2013, in respect of the announcement that Hudbay entered into an amended and restated precious metals purchase agreement with an affiliate of Silver Wheaton Corp. (incorporated by reference to Exhibits 99.1 to Hudbay’s Form 6-K (Commission File No. 001-34244), furnished to the Commission on November 14, 2013).

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4.7**	The material change report of HudBay Minerals Inc., dated December 10, 2013, in respect of the announcement of the completion of Hudbay’s offering of US$100 million of 9.50% senior unsecured notes (incorporated by reference to Exhibits 99.1 to Hudbay’s Form 6-K (Commission File No. 001-34244), furnished to the Commission on December 11, 2013).
4.8**	The press release of HudBay Minerals Inc., dated January 8, 2014, in respect of Hudbay’s 2014 production guidance and capital and exploration expenditure forecasts.
4.9**	The material change report of HudBay Minerals Inc., dated January 16, 2014, in respect of an offering of 18,200,000 common shares of Hudbay (incorporated by reference to Exhibits 99.1 to Hudbay’s Form 6-K (Commission File No. 001-34244), furnished to the Commission on January 17, 2014).
4.10**	The material change report of HudBay Minerals Inc., dated February 14, 2014, in respect of the Offer (incorporated by reference to Hudbay’s filing pursuant to Rule 425 on February 14, 2014).
4.11**	The press release of HudBay Minerals Inc., dated February 19, 2014, in respect of the announcement of Hudbay’s fourth quarter 2013 financial results (incorporated by reference to Hudbay’s filing pursuant to Rule 425 on February 19, 2014).
4.12**	The annual audited consolidated financial statements of HudBay Minerals Inc. for the years ended December 31, 2013 and 2012 and notes and the auditor’s report in respect thereof, together with the credit supporter disclosure filed concurrently therewith, and the management’s discussion and analysis of HudBay Minerals Inc. for the financial years ended December 31, 2013 and 2012 (incorporated by reference to Exhibits 99.1, 99.2 and 99.3 to Hudbay’s Form 6-K filed February 20, 2014).
4.13**	Notice of Variation and Extension, dated March 14, 2014.
4.14**	Notice of Variation and Extension, dated March 31, 2014.
4.15**	Notice of Change, dated April 24, 2014.
4.16**	Notice of Variation and Extension, dated May 5, 2014.
4.17*	Notice of Variation and Extension, dated May 16, 2014.
5.1**	Consent of Deloitte LLP.
5.2**	Consent of Goodmans LLP.
5.3**	Consent of Robert Carter.
5.4**	Consent of Cashel Meagher.
6.1**	Powers of Attorney (included on the signature pages of the Registration Statement on Form F-10 filed February 11, 2014).

* Filed herewith.

** Previously filed.

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EX-4.17

Exhibit 4.17

This document is important and requires your immediate attention. If you are in any doubt as to how to deal with it, you should consult your investment advisor, stockbroker, bank, trust company or other nominee.

May 16, 2014

NOTICE OF VARIATION AND EXTENSION

of HudBay Minerals Inc.’s offer to purchase

all of the issued and outstanding common shares of

AUGUSTA RESOURCE CORPORATION

for consideration per Augusta Share of
0.315 of a Hudbay Share

HudBay Minerals Inc. (the “Offeror”) hereby gives notice that it is varying its offer dated February 10, 2014, as amended by the Notice of Variation and Extension dated March 14, 2014, the Notice of Variation and Extension dated March 31, 2014, the Notice of Change dated April 24, 2014, and the Notice of Variation and Extension dated May 5, 2014 (collectively, the “Original Offer”), to purchase, on and subject to the terms and conditions of the Original Offer, as amended, all of the issued and outstanding common shares (the “Augusta Shares”) of Augusta Resource Corporation (“Augusta”), other than any Augusta Shares held directly or indirectly by the Offeror and its affiliates, including any Augusta Shares that may become issued and outstanding after February 10, 2014 but before the Expiry Time (as defined herein) upon the exercise, exchange or conversion of any securities of Augusta exercisable or exchangeable for, convertible into or otherwise conferring a right to acquire, any Augusta Shares, including, any options, warrants or convertible debentures (“Convertible Securities”), together with the associated rights issued under Augusta’s Shareholder Rights Plan, in order to extend the Original Offer to 5:00 p.m. (Toronto time) on May 27, 2014. The Original Offer, as amended and extended hereby, is referred to herein as the “Offer”.

THE ORIGINAL OFFER HAS BEEN EXTENDED, AND IS NOW OPEN FOR ACCEPTANCE
UNTIL 5:00 P.M. (TORONTO TIME) ON MAY 27, 2014 (THE “EXPIRY TIME”).

This Notice of Variation and Extension should be read in conjunction with the Original Offer and the take-over bid circular (the “Original Circular”) dated February 10, 2014, as previously amended (the Original Offer together with the Original Circular collectively referred to as the “Original Offer and Circular”), and the letter of transmittal (the “Letter of Transmittal”) and notice of guaranteed delivery (the “Notice of Guaranteed Delivery”) that accompanied the Original Offer and Circular. The Original Offer and Circular, as amended previously and by this Notice of Variation and Extension collectively constitute the “Offer and Circular”. Except as otherwise set forth herein, the terms and conditions previously set forth in the Original Offer and Circular, Letter of Transmittal and Notice of Guaranteed Delivery, each as previously amended, continue to be applicable in all respects. All references to the “Offer” in the Original Offer and Circular, the Letter of Transmittal, the Notice of Guaranteed Delivery and this Notice of Variation and Extension mean the Original Offer as amended hereby, and all references in such documents to the “Circular” or the “Offer and Circular” mean the Original Offer and Circular as amended hereby. Unless the context requires otherwise, capitalized terms used herein but not defined herein that are defined in the Original Offer and Circular have the respective meanings given to them in the Original Offer and Circular.

The offering of Hudbay Shares pursuant to the Offer is made by a Canadian issuer that is permitted, under a multi-jurisdictional disclosure system adopted by the United States, to prepare the Offer and Circular in accordance with the disclosure requirements of Canada. The Offer is subject to applicable disclosure requirements in Canada. Augusta Shareholders should be aware that such requirements are different from those of the United States and may differ from those in other jurisdictions. Financial statements included or incorporated by reference in the Offer and Circular have been prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board and are subject to Canadian auditing standards and auditor independence rules, and thus may not be comparable to financial statements of United States companies or companies incorporated in other jurisdictions. Augusta Shareholders in the United States should be aware that the disposition of Augusta Shares and acquisition of Hudbay Shares by them as described in the Offer and Circular may have tax consequences in the United States, Canada and other jurisdictions. Such consequences may not be fully described in the Offer and Circular and such holders are urged to consult their tax advisors. The enforcement by Augusta Shareholders of civil liabilities under U.S. federal or state securities laws or applicable laws of other jurisdictions may be affected adversely by the fact that the Offeror is incorporated under and governed by the laws of Canada, that its officers and directors may be residents of jurisdictions other than the United States or such other jurisdictions, that the experts named in the Circular may be residents of jurisdictions other than the United States or such other jurisdictions, that all or a substantial portion of the assets of the Offeror and such persons may be located outside the United States or such other jurisdictions, that some of Augusta’s officers and directors are resident outside the United States or such other jurisdictions and that all or a substantial portion of the assets of Augusta and Augusta’s officers and directors may be located outside the United States or such other jurisdictions.

THE HUDBAY SHARES AND THE OFFER HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE UNITED STATES SECURITIES AND EXCHANGE COMMISSION (“SEC”) OR ANY OTHER SECURITIES REGULATORY

AUTHORITY, NOR HAS THE SEC OR ANY OTHER SUCH AUTHORITY PASSED UPON THE ACCURACY OR ADEQUACY OF THE OFFER AND CIRCULAR. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

Prospective investors should be aware that, during the period of the Offer, the Offeror or its affiliates, directly or indirectly, may bid for or make purchases of the securities to be distributed or to be exchanged, or certain related securities, as permitted by applicable laws or regulations of Canada or its provinces or territories. Neither the Offeror nor any of its affiliates intends to make any such purchases during the period of the Offer.

Information has been incorporated by reference in the Offer and Circular from documents filed with the securities commissions or similar authorities in Canada. Copies of the documents incorporated by reference in the Offer and Circular are available electronically on SEDAR and EDGAR at www.sedar.com and www.sec.gov, respectively.

The Depositary for the Offer is:		Information Agent for the Offer is:
Equity Financial Trust Company		Kingsdale Shareholder Services
The Dealer Managers for the Offer are:
In Canada		In the United States
GMP Securities L.P.	BMO Nesbitt Burns Inc.	Griffiths McBurney Corp.	BMO Capital Markets Corp.

Augusta Shareholders who have validly deposited and not withdrawn their Augusta Shares need take no further action to accept the Offer.

Registered Augusta Shareholders who wish to accept the Offer must properly complete and execute the Letter of Transmittal (printed on YELLOW paper) that accompanied the Original Offer and Circular, or a manually executed facsimile thereof, and deposit it, at or prior to the Expiry Time, together with certificate(s) or Direct Registration System (DRS) Advices representing their Augusta Shares and all other required documents, with Equity Financial Trust Company (the “Depositary”) at its office in Toronto, Ontario specified in the Letter of Transmittal, in accordance with the instructions set out in the Letter of Transmittal (as set out in Section 3 of the Original Offer, “Manner of Acceptance — Letter of Transmittal”). Alternatively, registered Augusta Shareholders may accept the Offer by following the procedure for guaranteed delivery set out in Section 3 of the Original Offer, “Manner of Acceptance — Procedure for Guaranteed Delivery”, using the Notice of Guaranteed Delivery (printed on GREEN paper) that accompanied the Original Offer and Circular, or a manually executed facsimile thereof. Augusta Shareholders who hold their Augusta Shares with an investment advisor, stockbroker, bank, trust company or other nominee will not have received a Letter of Transmittal or Notice of Guaranteed Delivery, and should follow the instructions set out by such nominee to tender their Augusta Shares.

Persons whose Augusta Shares are registered in the name of an investment advisor, stockbroker, bank, trust company or other nominee should contact such nominee for assistance if they wish to accept the Offer in order to take the necessary steps to be able to deposit such Augusta Shares under the Offer. Nominees likely have established tendering cut-off times that are up to 48 hours prior to the Expiry Time. Augusta Shareholders must instruct their investment advisor, stockbroker, bank, trust company or other nominee promptly if they wish to tender.

Augusta Shareholders will not be required to pay any fee or commission if they accept the Offer by depositing their Augusta Shares directly with the Depositary or if they make use of the services of a Soliciting Dealer to accept the Offer.

Questions and requests for assistance may be directed to Kingsdale Shareholder Services (the “Information Agent”), who can be contacted at 1-866-229-8874 toll free in North America or at 1-416-867-2272 outside of North America or by e-mail at contactus@kingsdaleshareholder.com; or to the Depositary at the addresses indicated on the last page of this document and additional copies of this document, the Original Offer and Circular, the Letter of Transmittal and the Notice of Guaranteed Delivery, or any documents incorporated by reference or otherwise related to the Offer, may be obtained, without charge, upon request from the Depositary or the Information Agent at their respective offices shown on the last page of this document, and are accessible on the Canadian Securities Administrators’ website at www.sedar.com, on EDGAR at www.sec.gov and on the Offeror’s website at www.hudbayminerals.com. These website addresses are provided for informational purposes only and no information contained on, or accessible from, these websites is incorporated by reference in the Offer and Circular unless otherwise expressly indicated in the Offer and Circular.

The information contained in this document is current only as of the date of this document. The Offeror does not undertake to update any such information except as required by applicable Law. Information in this document and in the Original Offer and Circular related to Augusta has been compiled from public sources — see “INFORMATION CONCERNING AUGUSTA” in the Original Offer and Circular.

No broker, dealer, salesperson or other person has been authorized to give any information or make any representation other than those contained in this Notice of Variation and Extension or the Original Offer and Circular, and, if given or made, such information or representation must not be relied upon as having been authorized by the Offeror, the Depositary, the Information Agent or the Dealer Managers.

ADDITIONAL NOTICE TO UNITED STATES SHAREHOLDERS

AND OTHER SHAREHOLDERS OUTSIDE CANADA

The Offer is subject to Section 14(d) of the U.S. Securities Exchange Act of 1934, as amended (the “Exchange Act”), Regulation 14D promulgated by the SEC thereunder, Section 14(e) of the Exchange Act, and Regulation 14E promulgated by the SEC thereunder.

The Offeror has filed with the SEC a registration statement on Form F—10, which contains a prospectus relating to the Offer, a tender offer statement on a Schedule TO and other documents and information, as such documents have been amended, modified, supplemented or restated. AUGUSTA SHAREHOLDERS AND OTHER INTERESTED PARTIES ARE URGED TO READ THESE DOCUMENTS, ALL DOCUMENTS INCORPORATED BY REFERENCE, ALL OTHER APPLICABLE DOCUMENTS AND ANY AMENDMENTS OR SUPPLEMENTS TO ANY SUCH DOCUMENTS WHEN THEY BECOME AVAILABLE, BECAUSE EACH CONTAINS OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE OFFEROR, AUGUSTA AND THE OFFER. Materials filed with the Canadian securities regulatory authorities are available electronically without charge at www.sedar.com. Materials filed with the SEC are available electronically without charge at the SEC’s website, www.sec.gov. All such materials may also be obtained without charge at the Offeror’s website, www.hudbayminerals.com or by directing a written or oral request to the Information Agent for the Offer, Kingsdale Shareholder Services, at 1-866-229-8874 toll free in North America or at 1-416-867-2272 or by e-mail at contactus@kingsdaleshareholder.com or to the Vice President, Legal and Corporate Secretary of the Offeror at 25 York Street, Suite 800, Toronto, Ontario, telephone 1-416-362-8181.

Neither this document nor the Original Offer and Circular generally addresses the income tax consequences of the Offer to Augusta Shareholders in any jurisdiction outside Canada or the United States. Augusta Shareholders in a jurisdiction outside Canada or the United States should be aware that the disposition of Augusta Shares may have tax consequences which may not be described in this document or the Original Offer and Circular. Accordingly, Augusta Shareholders outside Canada and the United States should consult their own tax advisors with respect to tax considerations applicable to them.

The Original Offer and Circular also contains a cautionary note regarding mineral reserve and resource estimates prepared in accordance with Canadian National Instrument 43-101 — Standards of Disclosure for Mineral Projects — see “CAUTIONARY NOTE REGARDING MINERAL RESERVES AND MINERAL RESOURCES” in the Original Offer and Circular.

NOTICE TO HOLDERS OF CONVERTIBLE SECURITIES

The Offer is made only for Augusta Shares, together with the associated rights issued under the Shareholder Rights Plan, and is not made for any options, warrants or convertible debentures or any other rights to acquire Augusta Shares. Any holder of Convertible Securities who wishes to accept the Offer should, subject to and to the extent permitted by the terms of such Convertible Securities and applicable Law, exercise, exchange or convert such Convertible Securities in order to obtain certificates representing Augusta Shares and deposit such Augusta Shares in accordance with the Offer. See Section 1 of the Original Offer, “The Offer”. Any such exercise, exchange or conversion must be completed sufficiently in advance of the Expiry Time to ensure that the holder of such Convertible Securities will have received certificates representing the Augusta Shares issuable upon such exercise, exchange or conversion in time for deposit prior to the Expiry Time, or in sufficient time to comply with the procedures described in Section 3 of the Original Offer, “Manner of Acceptance — Procedure for Guaranteed Delivery”.

The tax consequences to holders of Convertible Securities of exercising or not exercising such securities are not described in the Offer and Circular. Holders of such Convertible Securities should consult their own tax advisors with respect to the potential tax consequences to them in connection with the decision to exercise or not exercise such securities.

iv

REPORTING CURRENCY AND CURRENCY EXCHANGE RATE INFORMATION

All dollar references in this document and the Original Offer and Circular are in Canadian dollars, except where otherwise indicated. On February 7, 2014, the Bank of Canada noon rate of exchange for the Canadian dollar, expressed in U.S. dollars, was Canadian $1.00 = United States $0.9076.

CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS

This Notice of Variation and Extension contains “forward-looking statements” and “forward-looking information” (collectively, “forward-looking information”) within the meaning of applicable Canadian and United States securities legislation. Forward-looking information includes information that relates to, among other things, statements with respect to the anticipated timing, mechanics and completion and settlement of the Offer, including the permitting of the Rosemont project. Forward-looking information is not, and cannot be, a guarantee of future results or events. Forward-looking information is based on, among other things, opinions, assumptions, estimates and analyses that, while considered reasonable by the Offeror at the date the forward-looking information is provided, inherently are subject to significant risks, uncertainties, contingencies and other factors that may cause actual results and events to be materially different from those expressed or implied by the forward-looking information. The material factors or assumptions that the Offeror identified and applied in drawing conclusions or making forecasts or projections set out in the forward looking information include, but are not limited to, the accuracy of Augusta’s public disclosure; no significant and continuing adverse changes in general economic conditions or conditions in the financial markets; that all required regulatory and governmental approvals for the Offer will be obtained and all other conditions to completion of the Offer will be satisfied or waived.

The risks, uncertainties, contingencies and other factors that may cause actual results to differ materially from those expressed or implied by the forward-looking information may include, but are not limited to, the market value of the Hudbay Shares received as consideration under the Offer and the impact of such issuance on the market price of the Hudbay Shares, the development of the Rosemont Project not occurring as planned, the inaccuracy of Augusta’s public disclosure upon which the Offer is predicated, the triggering of change of control provisions in Augusta’s agreements leading to adverse consequences, Augusta becoming a minority-owned or majority-owned subsidiary of the Offeror after consummation of the Offer, the possibility that the Offeror may remain a minority shareholder of Augusta after consummation of the Offer without the ability to control the management or direction of Augusta, as well as the risks discussed under the heading “Risk Factors” in the Original Offer and Circular and other documents filed with Canadian and U.S. securities regulatory authorities. Should one or more risk, uncertainty, contingency or other factor materialize or should any factor or assumption prove incorrect, actual results could vary materially from those expressed or implied in the forward-looking information. Accordingly, the reader should not place undue reliance on forward-looking information. The Offeror does not assume any obligation to update or revise any forward-looking information after the date of this Notice of Variation and Extension or to explain any material difference between subsequent actual events and any forward-looking information, except as required by applicable law.

The Original Offer and Circular also contains forward looking information and this cautionary note should be read in conjunction with the Cautionary Note Regarding Forward Looking Statements in the Original Offer and Circular.

NOTICE OF VARIATION AND EXTENSION

May 16, 2014

TO: THE HOLDERS OF COMMON SHARES OF AUGUSTA RESOURCE CORPORATION

This Notice of Variation and Extension amends and supplements the Original Offer and Circular, pursuant to which the Offeror is offering to purchase, on the terms and subject to the conditions of the Offer, all of the issued and outstanding Augusta Shares, other than any Augusta Shares held directly or indirectly by the Offeror and its affiliates, including any Augusta Shares that may become issued and outstanding upon the exercise, exchange or conversion of Convertible Securities after the date of the Original Offer and Circular but prior to the Expiry Time, together with the associated rights issued under the Shareholder Rights Plan, for consideration per Augusta Share of 0.315 of a Hudbay Share.

The Offeror continues to monitor developments with respect to Augusta’s applications for permits required for the Rosemont project. The Offeror is assessing, among other things, the potential implications of a letter dated May 13, 2014 that the U.S. Army Corps of Engineers (the “USACE”) is reported to have sent to Augusta. The USACE letter advises Augusta that, in the context of its Clean Water Act section 404 permit application, Augusta’s proposed compensatory mitigation is inadequate and USACE staff is changing its focus from compensatory mitigation to preparing a final permit decision.

On March 14, 2014, the Offeror waived the condition that there shall have been validly deposited under the Offer and not withdrawn, at or prior to the expiration of the Offer, such number of Augusta Shares that, together with the Augusta Shares already owned by the Offeror and its affiliates, represents not less than 662/3% of the Augusta Shares (calculated on a fully diluted basis). The Offeror has not waived any other conditions of the Offer described in Section 4 of the Original Offer, “Conditions of the Offer”, as amended.

1.Extension of the Offer

The Offeror has extended the time for acceptance of the Offer to 5:00 p.m. (Toronto time) on May 27, 2014. Accordingly, the definition of “Expiry Date” in the “Glossary” section of the Original Offer and Circular is hereby deleted and replaced by the following:

“Expiry Date” means May 27, 2014 or such later date or dates to which the Offer may be extended from time to time by the Offeror in accordance with Section 5 of the Offer, “Extension, Variation or Change of the Offer”;

In addition, all references to “5:00 p.m. (Toronto time) on May 16, 2014” in the Original Offer and Circular are amended to refer to “5:00 p.m. (Toronto time) on May 27, 2014”.

2.Time for Acceptance

The Offer is now open for acceptance until 5:00 p.m. (Toronto time) on May 27, 2014. Shareholders who have validly deposited and not withdrawn their Augusta Shares need take no further action to accept the Offer.  If, at the time immediately prior to 5:00 p.m. (Toronto time) on May 27, 2014, all of the conditions of the Offer are satisfied or waived by the Offeror, then the Initial Offering Period will end at such time and all Augusta Shares deposited under the Offer and not withdrawn will be taken up by the Offeror.  If any Augusta Shares are taken up under the Offer, the Offer will be extended and remain open for the deposit of Augusta Shares for not less than ten days from the date on which Augusta Shares are first taken up, which extended period will be a Subsequent Offering Period.

3.Manner of Acceptance

Augusta Shares may be deposited to the Offer in accordance with the provisions of Section 3 of the Original Offer, “Manner of Acceptance”.

4.Take-Up of and Payment for Deposited Augusta Shares

If all the conditions of the Offer have been satisfied or waived by the Offeror, the Offeror will take up Augusta Shares validly deposited under the Offer and not properly withdrawn no later than 9:00 a.m. on the first business day following the end of the Initial Offering Period.  The Offeror will pay for Augusta Shares taken up as soon as practicable thereafter and in any event within three business days thereafter.  By so taking up and paying for Augusta Shares validly deposited under the Offer and not properly withdrawn, the Offeror will comply with the requirement under Canadian law to take up such Augusta Shares within ten days following the end of the Initial Offering Period and paying for such shares within three business days thereafter. See Section 6 of the Original Offer, “Take Up of and Payment for Deposited Augusta Shares”.

5.Withdrawal of Deposited Augusta Shares

Augusta Shares deposited under the Offer may be withdrawn by or on behalf of the depositing Augusta Shareholder at any time before the Augusta Shares have been taken up by the Offeror under the Offer (including during any Subsequent Offering Period) and in the other circumstances described in Section 8 of the Original Offer,

“Withdrawal of Deposited Augusta Shares”. Except as so indicated or as otherwise required or permitted by applicable Laws, deposits of Augusta Shares are irrevocable.

6.Consequential Amendments to the Original Offer and Circular and Other Documents

The Original Offer and Circular, Letter of Transmittal and Notice of Guaranteed Delivery shall be read together with this Notice of Variation and Extension and are hereby amended to the extent necessary to reflect the amendments contemplated by, and the information contained in, this Notice of Variation and Extension.

Except as otherwise set forth in or amended by this Notice of Variation and Extension, the terms and conditions of the Offer and the information in the Original Offer and Circular, the Letter of Transmittal and the Notice of Guaranteed Delivery continue to be applicable in all respects.

7.Statutory Rights

Securities legislation in the provinces and territories of Canada provides security holders of Augusta with, in addition to any other rights they may have at law, one or more rights of rescission, price revision or to damages, if there is a misrepresentation in a circular or a notice that is required to be delivered to those security holders. However, such rights must be exercised within prescribed time limits. Security holders should refer to the applicable provisions of the securities legislation of their province or territory for particulars of those rights or consult with a lawyer.

8.Directors’ Approval

The contents of this Notice of Variation and Extension have been approved, and the sending thereof to the Augusta Shareholders has been authorized by the Hudbay Board of Directors.

APPROVAL AND CERTIFICATE OF HUDBAY MINERALS INC.

The foregoing, together with the Original Offer and Circular, contains no untrue statement of a material fact and does not omit to state a material fact that is required to be stated or that is necessary to make a statement not misleading in light of the circumstances in which it was made.

Dated: May 16, 2014.

(Signed) DAVID GAROFALO	(Signed) DAVID S. BRYSON
President and Chief Executive Officer	Senior Vice President and Chief Financial Officer
On behalf of the Board of Directors
(Signed) G. WESLEY VOORHEIS	(Signed) SARAH B. KAVANAGH
Director	Director

The Depositary for the Offer is:

By Registered Mail, Mail, Hand or Courier

Toronto

200 University Avenue
Suite 300
Toronto, Ontario

M5H 4H1

Attention:  Corporate Actions

Inquiries

North American Toll Free:  1-866-393-4891

Telephone:  416-361-0930 ext. 205

Facsimile:  416-361-0470

E-Mail:  corporateactions@equityfinancialtrust.com

THE INFORMATION AGENT FOR THE OFFER IS:

The Exchange Tower

130 King Street West, Suite 2950, P.O. Box 361

Toronto, Ontario M5X 1E2

North American Toll Free Phone:

1-866-229-8874

E-mail: contactus@kingsdaleshareholder.com

Facsimile: 416-867-2271

Toll Free Facsimile: 1-866-545-5580

Outside North America, Banks and Brokers Call Collect: 416-867-2272