Sharp reversals in the price of oil in July led energy hedge funds to a 9.5% decline during the month, according to new data, while funds investing more broadly in commodities also suffered amid expectations of a global economic slowdown.

Peter Laurelli, vice-president of US-based data provider HedgeFund.net, said: "The commodity sector had been an area of support for hedge funds in 2008, but as expectations of a global economic slowdown increased recent months the environment became more difficult in July."