Major upgrade of Ivanhoe’s Oyu Tolgoi resource

Vancouver – All of the copper and gold resources within planned open pits at the southern portion of Ivanhoe Mines’ (IVN-T) wholly owned Oyu Tolgoi deposit, in Mongolia, have now been upgraded to measured and indicated.

The new, updated independent estimate is based on extensive drilling since the last resource calculation was conducted in February 2003. A total of 539 holes totaling 255,000 metres have been drilled on the southern deposits at Oyu Tolgoi, compared to 155 holes used in the previous 2003 resource estimate.

Ivanhoe reports 934 holes now drilled on the entire project, totaling over 500,000 metres.

The new southern Oyu Tolgoi estimate, conducted by AMEC, outlines a measured and indicated resource of 1.06 billion tonnes grading 0.47% copper and 0.36 grams gold per tonne (copper equivalent grade of 0.71%). A cut-off grade of 0.3% copper equivalent was utilized to a depth of 560 metres, and 0.6% copper equivalent below 560 metres depth. Contained metals calculate out to about 11.2 billion pounds of copper and 12.4 million oz. gold.

Additional inferred resources, primarily in the Hugo Dummett deposits, are 1.2 billion tonnes grading 1.25% copper and 0.24 grams gold (copper equivalent grade of 1.38%). A 0.6% copper equivalent cut-off grade was used. Contained metals are about 33.7 billion pounds of copper and 9.4 million oz. gold.

The company will incorporate these southern Oyu Tolgoi resource estimates into its full feasibility study, scheduled for completion by early-2005, for a planned open pit operation. The open pit feasibility study is currently underway, concurrent with an underground pre-feasibility study on the Hugo Dummett deposits, and will provide an integrated development plan for the massive copper-gold porphyry deposit.

Ivanhoe plans to have Oyu Tolgoi in production by mid-2007.