LONDON, March 7 (Reuters) - Hedge fund Odey Asset Management has launched a new commodities fund which, according to the Financial Times, has taken a short position in Rio Tinto's giant Oyu Tolgoi copper mine in Mongolia.

The Odey Concentrated Natural Resources Fund, which launched on March 1, will invest in the commodity sector, using both long and short positions in a range of asset classes, but mostly equities, according to Odey's website.

A spokeswoman for Odey declined to provide details, but the Financial Times reported the largest short position of the fund was in Turquoise Hill Resources, the Canadian firm that partly owns Oyu Tolgoi.

The government of Mongolia owns 34 percent of Oyu Tolgoi with the remainder held by Turquoise Hill, which in turn is 51 percent owned by Rio Tinto.

Turquoise Hill shares have shed 46 percent over the past 12 months amid delays to an underground expansion at Oyu Tolgoi that would create one of the world's biggest copper suppliers.

At the end of last year, Rio and Mongolia signed a power supply deal, regarded as the last hurdle for the extension of the mine.

First production at the $5.3 billion underground expansion located near the southern border with China is scheduled for early next decade.

In January, Mongolia's anti-graft body said the country was working with overseas investigators to look into claims of corruption at Oyu Tolgoi. (Reporting by Eric Onstad; Editing by Mark Potter)