Cazenove, the UK investment bank, was yesterday saddled with a leadership vacuum after Robert Pickering quit as chief executive, forcing David Mayhew, chairman, to run the company while a successor is found.

Mr Pickering's departure comes four years after Cazenove put most of its business into a joint venture with JPMorgan, the US investment bank, and nearly 12 months since key staff were allowed to sell restricted stock.