Northern Orion Resources Inc.
TSX : NNO
AMEX : NTO

Northern Orion Resources Inc.

August 20, 2007 21:13 ET

Northern Orion Reports Minimal Exposure to Canadian Asset-Backed Commercial Paper

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Aug. 20, 2007) - NORTHERN ORION RESOURCES INC. (TSX:NNO)(AMEX:NTO) today reported that it has cash and cash equivalents totaling approximately U.S.$240 million. Of this amount, approximately U.S.$14 million is invested in a Canadian asset-backed commercial paper fund, representing 5.8% of its overall cash and cash equivalent investments. The fund has been given an R1-high rating from the Dominion Bond Rating Service Limited ("DBRS") and has a maturity date of August 24, 2007.

The remainder of the Company's cash position is invested in term deposits, bank notes and other funds carrying the highest possible investment grades as determined by DBRS. The Company does not consider any of these investments at risk.

In addition, the Company's 12.5%-owned Alumbrera Mine has approximately U.S.$130 million in cash and cash equivalents that have no exposure to Canadian asset-backed commercial paper.

David Cohen, President and CEO

Forward-Looking Statements: This news release includes forward-looking statements which are subject to a variety of risks and uncertainties which could cause actual events or results to differ from those reflected in the forward-looking statements, including, without limitation, risks and uncertainties relating to the repayment of Canadian asset-backed commercial paper held by Northern Orion. Such statements also involve known and unknown risks, uncertainties and other factors which may cause the actual timing, results, performance or achievement of Northern Orion to be materially different from those expressed or implied by such forward-looking statements. Such factors include, among others, risks related to international operations, risks related to economic and political stability in Argentina, and possible changes in government regulation as well as those factors discussed in the section entitled "Risk Factors" in Northern Orion's Renewal Annual Information Form attached to Northern Orion's latest Form 40-F on file with the United States Securities and Exchange Commission in Washington, D.C. Although Northern Orion has attempted to identify important factors that could cause actual timing and results to differ materially, there may be other factors that cause timing or results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate as actual results and future events could differ materially from those anticipated in such statements. Northern Orion disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Accordingly, readers should not place undue reliance on forward-looking statements.

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