Investors expecting the Chinese currency, the renminbi, to become freely convertible may be disappointed, according to Jim O'Neill, chief economist at Goldman Sachs.

“Maybe in 10 years' time, China will say ‘We've got this far without floating the currency' and impose a controlled foreign exchange system on the rest of the world,” said Mr O'Neill, who came up with the Bric concept, which groups Brazil, Russia, India and China on the basis that they will overtake the world's richest economies by 2050.

If Mr O'Neill is right, foreign investors in China may need to rethink assumptions about the currency's direction. The current controlled exchange rate against the dollar has left the renminbi undervalued in terms of purchasing power parity. The International Monetary Fund has estimated that, although the official exchange rate is Y6.8 to $1, it takes just Y3.8 to buy a dollar's worth of goods. If the currency were to rise to this level, investments in China would effectively double in value.