The dollar surged to a two-year high against the pound and a six-month peak against the euro on Friday, as fears about spreading economic gloom triggered a sell-off in commodities.

Against sterling, the US currency notched up its 11th consecutive day of gains – its longest uninterrupted rise in more than 35 years – as markets became increasingly convinced that the US was best-placed to weather the global downturn.

Prices for crude oil, platinum, copper, aluminium, corn and soyabeans have also retreated from records hit this year, prompting speculation that commodity prices have reached a turning point.

“The golden age when commodity prices could only go up is gone,” said Marco Annunziata, chief economist at Unicredit.

Analysts were divided on the outlook for commodities. Lehman Brothers believed oil prices had peaked, while Goldman Sachs repeated its forecast that they would hit $149 by the end of the year.