Since China began to liberalise its currency last year, debate has raged over whether and when renminbi will become a major reserve currency in its own right. The ongoing sovereign crisis and the recent downgrade of the US's credit rating by Standard & Poor's appear to have accelerated the pace of change in the composition of central bank reserves.

"The US downgrade in August was a really key driver of interest in renminbi. In the days following the downgrade we had several enquiries from