Companies in emerging markets have been flooding western exchanges with shares this year, as investors have scrambled to buy into the post-crisis resurgence in developing economies.

Depositary receipts, or DRs, are instruments that reference foreign shares held on deposit by a western bank. Initial public offerings by overseas companies using DRs have jumped 68% in the first 11 months of the year, compared to the same period in 2008, according to JP Morgan's year end industry report, published yesterday.