If the City of London is sometimes regarded as a gentleman's club, then the UK Takeover Panel's decision to punish three investors found guilty of breaking its code by "cold-shouldering" them will do little to dispel that impression.

The body that polices London's mergers-and-acquisitions market found Brian Myerson, Daniel Posen and Brian Padgett guilty of colluding illegally to gain control of listed company Principal Capital Investment Trust and then orchestrating a cover-up.