Some of the world's largest sovereign wealth funds are seeking to reduce their exposure to the US dollar in a sign of global concern about the currency.

One big sovereign fund in the Gulf has cut its dollar-denominated holdings from more than 80 per cent a year ago to less than 60 per cent, while China's State Administration of Foreign Exchange (SAFE) has been looking to strike deals with private equity firms in Europe as a part of a strategy to reduce its dollar holdings.