Icap, the world’s largest inter-dealer broker, said it believed over-the-counter derivatives markets had “reached an inflection point” where it was likely that many instruments that had long traded over the telephone might shift into electronic dealing.

Mark Yallop, Icap chief operating officer, said there had been few “strong incentives” for the shift to occur. Recent volatility in OTC derivatives, caused by turmoil in financial markets, had made Icap more reliant upon traditional but lower-margin voice broking.