It has been an irritant for years but the phenomenal growth in hedge fund assets under management is becoming a serious threat to the stability of traditional firms. Lazard Asset Management, still suffering the loss of fund manager William von Mueffling last year, has just lost its UK equity star Simon Roberts to BlueCrest.

The ranks of talent at firms ranging from Baring Asset Management to Merrill Lynch Investment Managers have been thinned by defections. The siren call from hedge funds has become more strident, as they search for additional managers to look after the money flooding their way.