Casualties from the global market turmoil began to mount on Wednesday, as two initial public offerings in London were postponed and a prominent US market debutant saw its shares fall by up to 15 per cent ? the worst first-day drop for more than two years.

In London, both CMC Markets, which provides spread-betting and foreign exchange services, and Sigma Capital Investments, the Black Sea property group, said they remained committed to their IPOs, but would wait until the markets were less volatile.