TORONTO, ONTARIO--(Marketwire - March 27, 2013) - HudBay Minerals Inc. ("Hudbay" or the "company") (News - Market indicators)(NYSE:HBM) today announced an increase to its copper equivalent proven and probable mineral reserves for the third consecutive year. Copper equivalent proven and probable mineral reserves increased by 12% to approximately 3.6 million tonnes, including approximately 4 million ounces of precious metal equivalent proven and probable reserves, which increased by 16% from 2012. In addition, Hudbay has approximately 1.9 million tonnes of copper equivalent measured and indicated resources and approximately 2.2 million tonnes of copper equivalent inferred resources, including approximately 2 million ounces of precious metal equivalent measured and indicated resources and approximately 3 million ounces of precious metal equivalent inferred resources.

Exploration success and resource evaluation accounted for approximately 88% of the increase in copper equivalent reserves and resources and the entire increase in precious metal equivalent reserves and resources, with the balance due to revised commodity price and exchange rate assumptions.

¹All mineral resources referred to in this news release are exclusive of and additional to stated mineral reserves. Mineral resources that are not mineral reserves do not have demonstrated economic viability. Overall copper equivalent reserves and resources and precious metal equivalent reserves and resources are in-situ contained metal based on estimated reserves and resources at Hudbay's Constancia, Pampacancha, 777, Lalor, Reed, Back Forty, Tom and Jason and Lost properties. Copper equivalent metal for 2013 calculated using a copper price of US$2.75 per pound, zinc price of US$0.95 per pound, gold price of US$1,250.00 per ounce, silver price of US$25.00 per ounce, lead price of US$0.90 per pound and molybdenum price of US$14.00 per pound. Copper equivalent metal for 2012 was calculated using a copper price of US$2.75 per pound, zinc price of US$0.95 per pound, gold price of US$1,100.00 per ounce, silver price of US$22.00 per ounce, lead price of US$0.85 per pound and molybdenum price of US$13.00 per pound.

²For 2013 and 2012, precious metal equivalent reserves and resources include gold and silver only, expressed in ounces of gold with silver converted to gold at a ratio of 50:1.

On a per share basis, Hudbay's copper equivalent proven and probable reserves grew to 46.1 pounds per share compared to 41.3 pounds per share in 2012. Copper equivalent measured and indicated resources grew to 24.1 pounds per share compared to 11.9 pounds per share in 2012 and copper equivalent inferred resources grew to 28.3 pounds per share compared to 21.6 pounds per share in 2012.

Hudbay also announced that, based on production results to date in 2013 from the Lalor mine, the company expects to achieve commercial production from the first phase of Lalor as at March 31, 2013, with Lalor initial production expected to contribute to profit starting in April 2013.

"We have grown our metals reserves and resources per share for the third consecutive year and, in doing so, we have been able to provide our shareholders with increasing leverage to commodity exposure on a per share basis," said David Garofalo, President and Chief Executive Officer. "Much of this success was attributed to growth from Constancia and the higher grade Pampacancha deposit in Peru. As we continue our Peru exploration program and begin to explore from underground at our Lalor project, we are hopeful we will continue increasing reserves and resources going forward."

Additional Information

The reserve and resource estimates included in this news release were prepared in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101") and the Canadian Institute on Mining, Metallurgy and Petroleum Standards on Mineral Resources and Reserves: Definitions and Guidelines. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

Manitoba

• To estimate mineral reserves, measured and indicated mineral resources were first estimated in a 12-step process, which includes determination of the integrity and validation of the data collected, including confirmation of specific gravity, assay results and methods of data recording. The process also includes determining the appropriate geological model, selection of data and the application of statistical models including probability plots and restrictive kriging to establish continuity and model validation. The resultant estimates of measured and indicated mineral resources are then converted to proven and probable mineral reserves by the application of mining dilution and recovery, as well as the determination of economic viability using full cost analysis. Other factors such as depletion from production are applied as appropriate.
  
  
• Estimated inferred mineral resources within our mines were estimated by a similar 12-step process, used to estimate measured and indicated resources.
  
  
• The zinc price used for mineral reserve and resource estimations for the Manitoba mines was US$1.01 per pound (includes premium), the copper price was US$2.75 per pound, the gold price was US$1,250.00 per ounce and the silver price was US$25.00 per ounce using an exchange of 1.05 C$/US$.
  
  
• For additional details relating to the estimates of mineral reserves and resources at the 777 mine, including data verification and quality assurance/quality control processes refer to the "Technical Report 777 Mine, Flin Flon, Manitoba, Canada" dated October 15, 2012 on SEDAR.
  
  
• For additional details relating to the estimates of mineral reserves and resources at the Lalor project, including data verification and quality assurance/quality control processes refer to the "Pre-Feasibility Study Technical Report, on the Lalor Deposit" dated March 29, 2012 on SEDAR.
  
  

Peru

• For additional details relating to the estimates of mineral reserves and resources at the Constancia project, including data verification and quality assurance/quality control processes refer to "The Constancia Project, National Instrument 43-101 Technical Report" as filed on SEDAR by Hudbay on November 6, 2012.
  
  
• Copper Equivalent % is calculated for the in situ value of contained metals using the following $US metal price assumptions, Cu=2.75/lb Mo=13.00/lb, Ag=22.00/oz and Au=1,100.00/oz.
  
  
• The Constancia and Pampacancha mineral reserves are based on a Peruvian Sole: US Dollar exchange rate of 2.85:1 and the following long term metals prices: Cu US$2.75/lb; Ag US$23.00/oz; Au US$1,150.00/oz; and Mo US$14.00/lb.
  
  
• The Constancia mineral resources are reported at a 0.12% copper cut-off and are based on the following assumptions: a copper price of US$2.88/lb, a molybdenum price of US$14.00/lb, copper recovery of 89%, molybdenum recovery of 60%, processing cost of US$5.50/t and mining cost of US$1.30/t.
  
  
• The Pampacancha mineral resources are reported at a 0.20% copper cut-off and are based on a Peruvian Sole: US Dollar exchange rate of 2.85:1 and the following long term metals prices: Cu US$2.75/lb; Ag US$23.00/oz; Au US$1,150.00/oz; and Mo US$14.00/lb.
  
  
• Measured and indicated mineral resources were estimated in house. The process includes determination of the integrity and validation of the data collected, including confirmation of specific gravity, assay results and methods of data recording. The process also includes determining the appropriate geological model, selection of data and the application of statistical models including probability plots to establish continuity and model validation.
  
  

Reed

• The weighted average (based on planned production tonnage) used in the Reed pre-feasibility study for mineral reserve estimation for copper was US$2.95 per pound, the gold price was US$1,269.09 per ounce and the silver price was US$24.78 per ounce using an exchange rate of 1.034 C$/US$.
  
  

Other Properties

• Back Forty mineral resources were estimated using NSR cut-off values based on metal price assumptions of US$0.96 per pound zinc, US$3.65 per pound copper, US$1.01 per pound lead, US$1,456.36 per troy ounce gold and US$27.78 per troy ounce silver and applying recoveries for each metallurgical domains determined for the deposit. Back Forty mineralization offering reasonable prospects for economic extraction by open pit were determined using the Lerchs-Grossman optimizing algorithm. Optimization parameters were based on costs derived in the "Technical Report, Preliminary Economic Assessment on the Back Forty Deposit, Menominee County, Michigan, USA" dated April 26, 2012 as well as updated metallurgical recoveries and updated metal prices. Average NSR cut-off values for the open pit mineral resources were US$27.75/tonne and average NSR cut-off values for an underground mining scenario were US$66.45/tonne.
  
  
• Tom and Jason Metal prices used (US$0.57/lb Zn, US$0.35/lb Pb and US$7.00/oz Ag) and a gross dollar value cut-off of US$50/tonne. Ag values were capped at 550 g/t. For additional detail relating to the Tom/Jason mineral resource estimates see "Technical Report on the Tom and Jason Deposits, Yukon territory, Canada" as filed on SEDAR by Hudbay on May 24, 2007.
  
  

Qualified Person

The technical and scientific information in this news release related to the Constancia project has been approved by Cashel Meagher, P. Geo, Hudbay's Vice-President, South America. The technical and scientific information related to all other sites and projects contained in this news release has been approved by Robert Carter, P. Eng, Hudbay's Director, Technical Services. Messrs. Meagher and Carter are qualified persons pursuant to NI 43-101.

Forward-Looking Information

This news release contains "forward-looking statements" and "forward-looking information" (collectively, "forward-looking information") within the meaning of applicable Canadian and United States securities legislation. All information contained in this news release, other than statements of current and historical fact, is forward-looking information. Forward-looking information includes information that relates to, among other things, our objectives, strategies, and intentions and future financial and operating performance and prospects. Often, but not always, forward-looking information can be identified by the use of words such as "plans", "expects", "budget", "guidance", "scheduled", "estimates", "forecasts", "strategy", "target", "intends", "objective", "goal", "understands", "anticipates" and "believes" (and variations of these or similar words) and statements that certain actions, events or results "may", "could", "would", "should", "might" "occur" or "be achieved" or "will be taken" (and variations of these or similar expressions). All of the forward-looking information in this news release is qualified by this cautionary statement.

Forward-looking information includes, but is not limited to, continued production at Hudbay's 777 and Lalor mines, continued processing at the company's Flin Flon concentrator, Snow Lake concentrator and Flin Flon zinc plant, Hudbay's ability to develop its Lalor, Constancia and Reed projects and the anticipated scope of, cost of and development plans for, these projects, anticipated timing of Hudbay's projects and events that may affect the company's projects, Hudbay's expectation that it will receive the remaining US$250 million deposit payment under the precious metals stream transaction with Silver Wheaton Corp., the anticipated effect of external factors on revenue, such as commodity prices, anticipated exploration and development expenditures and activities and the possible success of such activities, estimation of mineral reserves and resources, mine life projections, timing and amount of estimated future production, reclamation costs, economic outlook, government regulation of mining operations, and business and acquisition strategies.

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 company 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 Hudbay identified and were applied by the company in drawing conclusions or making forecasts or projections set out in the forward-looking information include, but are not limited to:

• the success of mining, processing, exploration and development activities;
• the accuracy of geological, mining and metallurgical estimates;
• the costs of production;
• the supply and demand for metals Hudbay produces;
• the volatility of commodity prices;
• the volatility in foreign exchange rates;
• the supply and availability of concentrate for Hudbay's processing facilities;
• the supply and availability of reagents for Hudbay's concentrators;
• the availability of third party processing facilities for Hudbay's concentrate;
• the supply and availability of all forms of energy and fuels at reasonable prices;
• the availability of transportation services at reasonable prices;
• no significant unanticipated operational or technical difficulties;
• the availability of financing for Hudbay's exploration and development projects and activities;
• the ability to complete project targets on time and on budget and other events that may affect Hudbay's ability to develop its projects;
• the timing and receipt of various regulatory and governmental approvals;
• the availability of personnel for Hudbay's exploration, development and operational projects and ongoing employee relations;
• maintaining good relations with the communities in which Hudbay operates, including the communities surrounding the company's Constancia project and First Nations communities surrounding the company's Lalor and Reed projects;
• no significant unanticipated challenges with stakeholders at Hudbay's various projects;
• no significant unanticipated events relating to regulatory, environmental, health and safety matters;
• no contests over title to Hudbay's properties, including as a result of rights or claimed rights of aboriginal peoples;
• the timing and possible outcome of pending litigation and no significant unanticipated litigation;
• certain tax matters, including, but not limited to current tax laws and regulations; and
• no significant and continuing adverse changes in general economic conditions or conditions in the financial markets.

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, risks generally associated with the mining industry, such as economic factors (including future commodity prices, currency fluctuations and energy prices), uncertainties related to the development and operation of the company's projects, depletion of its reserves, risks related to political or social unrest or change and those in respect of aboriginal and community relations and title claims, operational risks and hazards, including unanticipated environmental, industrial and geological events and developments and the inability to insure against all risks, failure of plant, equipment, processes, transportation and other infrastructure to operate as anticipated, compliance with government and environmental regulations, including permitting requirements and anti-bribery legislation, dependence on key personnel and employee relations, volatile financial markets that may affect our ability to obtain financing on acceptable terms, uncertainties related to the geology, continuity, grade and estimates of mineral reserves and resources and the potential for variations in grade and recovery rates, uncertain costs of reclamation activities, Hudbay's ability to comply with the company's pension and other post-retirement obligations, Hudbay's ability to abide by the covenants in the company's debt instruments, as well as the risks discussed under the heading "Risk Factors" in Hudbay's most recent Annual Information Form and Form 40-F and MD&A dated February 20, 2013.

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, you should not place undue reliance on forward-looking information. Hudbay does not assume any obligation to update or revise any forward-looking information after the date of this news release or to explain any material difference between subsequent actual events and any forward-looking information, except as required by applicable law.

Note to United States Investors

Information concerning Hudbay's mineral properties has been prepared in accordance with the requirements of Canadian securities laws, which differ in material respects from the requirements of the Securities and Exchange Commission ("SEC") Industry Guide 7.

Under SEC Industry Guide 7, mineralization may not be classified as a "reserve" unless the determination has been made that the mineralization could be economically and legally produced or extracted at the time of the reserve determination, and the SEC does not recognize the reporting of mineral deposits which do not meet the United States Industry Guide 7 definition of "Reserve".

In accordance with NI 43-101 of the Canadian Securities Administrators, the terms "mineral reserve", "proven mineral reserve", "probable mineral reserve", "mineral resource", "measured mineral resource", "indicated mineral resource" and "inferred mineral resource" are defined in the Canadian Institute of Mining, Metallurgy and Petroleum (the "CIM") Definition Standards for Mineral Resources and Mineral Reserves adopted by the CIM Council on December 11, 2005.

While the terms "mineral resource", "measured mineral resource", "indicated mineral resource" and "inferred mineral resource" are recognized and required by NI 43-101, the SEC does not recognize them. You are cautioned that, except for that portion of mineral resources classified as mineral reserves, mineral resources do not have demonstrated economic value. Inferred mineral resources have a high degree of uncertainty as to their existence and as to whether they can be economically or legally mined.

It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher category. Therefore, you are cautioned not to assume that all or any part of an inferred mineral resource exists, that it can be economically or legally mined, or that it will ever be upgraded to a higher category. Likewise, you are cautioned not to assume that all or any part of measured or indicated mineral resources will ever be upgraded into mineral reserves. You are urged to consider closely the disclosure on the technical terms in Schedule A "Glossary of Mining Terms" of Hudbay's annual information form for the fiscal year ended December 31, 2011, available on SEDAR at www.sedar.com and incorporated by reference as Exhibit 99.1 in Hudbay's Form 40-F dated April 2, 2012 (File No. 001-34244).

About Hudbay

Hudbay (News - Market indicators)(NYSE:HBM) is a Canadian integrated mining company with assets in North and South America principally focused on the discovery, production and marketing of base and precious metals. Hudbay's objective is to maximize shareholder value through efficient operations, organic growth and accretive acquisitions, while maintaining its financial strength. A member of the S&P/TSX Composite Index and the S&P/TSX Global Mining Index, Hudbay is committed to high standards of corporate governance and sustainability. Further information about Hudbay can be found on www.hudbayminerals.com.