Cenkos chief executive Simon Melling stands down in surprise resignation

Melling, who has held the job for the past two years and was previously finance director, is leaving "to pursue other interests".

It is understood that he does not have another job to go to and is standing down for personal family reasons.

He has agreed to remain chief executive for up to three months unless a successor can be appointed earlier.

That suggests Cenkos is looking for an outside candidate to head the business.

Senior internal executives such as Nicholas Wells, head of corporate finance, Jim Durkin, head of corporate broking, and Peter Isard, head of institutional equities are not thought to have applied for the job.

Similarly, Andy Stewart, founder of both Cenkos and Collins Stewart, who still owns 12% of the company, is not expected to return to run the business.

He stood down from the board a year ago and has since enjoyed success with his main interest - owning racehorses.

Peter Sullivan, chairman of Cenkos, said: "Simon's commitment has been a driving force since Day One and we are very grateful for all that he has done. The board will be sorry to see him move on and he leaves with our best wishes."

Cenkos said that despite challenging financial markets it is trading profitably.