for Its Los Azules Copper Deposit

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TORONTO, ONTARIO--(Marketwire - Dec. 16, 2010) - Minera Andes Inc. (TSX:MAI)(OTCBB:MNEAF) is pleased to announce the results of an updated preliminary assessment ("PA") on its 100% owned Los Azules Copper Project (the "Project") located in the San Juan Province of western central Argentina. It is based on the updated resource estimate announced in June 2010 and higher base case metal price assumptions.

Using a Copper price of $3.00/ lb
Base case pre-tax Net Present Value ("NPV") is $2.8 billion and the Internal Rate of Return ("IRR") is 21.4%, at a discount rate of 8%
Life of mine Cash Operating Costs of $0.96/lb of copper net of gold and silver by-product credits.
Initial Capital $2.9 billion
Capital Payback in 3 years.
Mine life of 25 years.



Rob McEwen, Chairman and CEO of Minera Andes, said:



"We are advancingthe engineering studies on Los Azules to systematically de-risk the project. The field season is just getting underway, and we are currently mobilizing the first two of five drill rigs to the project. In addition to continuing the infill and step out drilling, we will start to test some of the newly identified deeper geophysical targets this season."



The Los Azules Copper Project is an advanced-stage porphyry copper exploration project located in the cordilleran region of San Juan Province, Argentina near the border with Chile. The deposit is a typical porphyry copper system in that the upper part of the system consists of a barren leached cap, which is underlain by a high-grade secondary enrichment blanket, and the primary mineralization below the secondary enrichment zone extends to at least 650 meters, which is the depth of the deepest holes drilled to date. The deposit is approximately one kilometer wide by four kilometers long, and it is open in several directions.


Highlights of the updated Preliminary Assessment are shown below. Details may be found in an updatedtechnical report which will be posted on SEDAR following the issuance of this news release.



NPV ($3.00/lb Cu, 8% discount rate)
$2,826 million



IRR
21.4%



Initial Capital Expenditure
$2,851 million



LOM Average Operating Costs
$7.82/t ore



LOM C-1 Cash Costs (net by-product credits)
$0.96/lb Cu mined



Nominal Mill Capacity
100,000 tpd



Annual Throughput
36 million tonnes



Mine Life
25.4 years



Life-of-Mine Strip Ratio
1.37



LOM average annual copper-in-concentrate production
169,100 tonnes



First 5 Years average annual copper-in-concentrate production
226,500 tonnes








All monetary amounts are expressed in US dollars unless otherwise stated. The PA is preliminary in nature and includes the use of inferred resources which are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves. Thus, there is no certainty that the results of the PA will be realized. Actual results may vary, perhaps materially.The level of accuracy for Preliminary Assessment estimates is approximately +/- 35%.







Compared to the previous Preliminary Assessment released in March 2009, the NPV discounted at 8% has increased from $496 million to $2.9 billion and the IRR has increased from 10.8% to 21.4%. In addition, the payback of pre-production capital has decreased from 6.4 years to 3.1 years from the start of production.


The main driver of the improved project economics is that the base case copper price has been increased from $1.90/pound to $3.00/pound. Specifically, the higher copper price added approximately $3.2 billion to the NPV, and the increased resources added approximately $2.1 billion.


The benefits of the higher copper price and increased resources were significantly offset by increases in the estimated operating costs ($695 million), capital costs ($100 million) and export retention taxes and royalties ($3.4billion).


The updated Preliminary Assessment also incorporates updated property status and ownership information, revised locations for the project facilities, and an updated geological interpretation.



Project Economics



The Preliminary Assessment contains a cash flow valuation model based upon the geological and engineering work completed to date and technical and cost inputs developed by Samuel Engineering, Inc., Ausenco Vector and MTB Project Management Professionals, Inc. The base case was developed using long term forecast metal prices of $3.00/lb for copper, $980/oz for gold, and $15.60/oz for silver.


The following chart shows the sensitivity of the base case's NPV and IRR to changes in the copper price: (8% real discount rate).



To view the chart, please visit the following link:
>http://media3.marketwire.com/docs/MAIchart2.jpg.




About Minera Andes



Minera Andes is an exploration company exploring for gold, silver and copper in Argentina with three significant assets: A 49% interest in Minera Santa Cruz SA, owner of the San Jose Mine in close proximity to Andean Resources' Cerro Negro project; 100% ownership of the Los Azules copper deposit with an inferred mineral resource of 10.3 billion pounds of copper and an indicated resource of 2.2 billion pounds of copper; and, 100% ownership of a portfolio of exploration properties bordering Andean's Cerro Negro project in Santa Cruz Province. The Corporation had $10 million USD in cash as at September 30, 2010 with no bank debt. Rob McEwen, Chairman and CEO, owns 33% of the company.


This news release has been submitted by Jim Duff, Chief Operating Officer of the Corporation. For further information, please contact Jim Duff or visit our Website:




Mineral resources are generated using ordinary kriging with a nominal block size of 20x20x15m. Block grade estimates are derived from drill hole sample results and the interpretation of a geologic model which relates to the spatial distribution of copper, gold, silver and molybdenum in the deposit. There are a total of 114 drill holes in the Los Azules database with a cumulative length of 30,997 meters and a total of 15,260 samples analyzed for a suite of elements including total copper, gold, silver and molybdenum. A total of 58 of the drill holes have some portion of the sample intervals tested for sequential copper analysis. This information contributed to the development of the mineral zone domains. The portion of the new mineral resource that has been defined as "indicated" is based on a drilling configuration that exhibits the degree of continuity required for higher level mineral resources. Inferred mineral resources are limited to blocks within a maximum distance of 200 meters from a drill hole. As required by NI 43-101, the possible future economic viability of the mineral resource has been exhibited by restriction within a pit shell derived about the copper content in indicated and inferred class blocks at a copper price of $2.50/lb, total operating costs of $5.25/tonne and an average pit slope of 34 degrees. Mineral resources are presented at a cut-off grade of 0.35%Cu, which is the same base cut-off grade used in the 2008 mineral resource estimate. These are mineral resources, not mineral reserves.




For further information in respect of the Los Azules project please refer to the technical report entitled "Canadian National Instrument 43-101 Technical Report Updated Preliminary Assessment, Los Azules Project, San Juan Province, Argentina" dated December 1, 2010, the "Los Azules Report." This report will be made available on SEDAR (
http://www.sedar.com/">www.sedar.com
) concurrent with the filing of this news release. Inferred mineral resources are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves. There is no certainty that the project as described in the Los Azules Report will be realized.




Cautionary Note to U.S. Investors:




All resource estimates reported by the Corporation were calculated in accordance with NI 43-101 and the Canadian Institute of Mining and Metallurgy Classification system. These standards differ significantly from the requirements of the U.S. Securities and Exchange Commission. Mineral resources which are not mineral reserves do not have demonstrated economic viability.