VANCOUVER - Shares in Taseko Mines (TSX:TKO) nosedived Monday in their first trading after a federal review panel said the company's proposed open-pit gold-copper mine in B.C. would pose significant threats to the environment.

An independent study on the Prosperity Gold-Copper Mine concluded "the project would result in significant adverse environmental effects on fish and fish habitat, on navigation, on the current use of lands and resources for traditional purposes by First Nations and on cultural heritage, and on certain potential or established Aboriginal rights or title,'' in a report submitted Friday to federal Environment Minister Jim Prentice.

Prentice will now take the report to the federal cabinet for a final decision.

The panel also said the project could also have significant effects on grizzly bears in the region.

The $800-million project 125 kilometres southwest of Williams Lake, B.C., would have a 20-year lifespan and include an onsite mill, access road, and 125-kilometre long power transmission line.

Taseko has said the project would generate hundreds of direct and indirect jobs in B.C.'s Cariboo-Chilcotin region. Last January, the B.C. government concluded that while the project would have negative environmental effects, the mine was justified.

Taseko shares were down 74 cents or 17.8 per cent at $3.42 in midday trading on the Toronto Stock Exchange.

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