The Association of British Insurers said on Friday it would issue a warning to shareholders over plans by Shire, the UK-listed speciality pharmaceuticals group, to appoint its chief executive as non-executive chairman.

Peter Montagnon, director of investment affairs at the ABI, said that before Shire’s annual meeting next June, his organisation would place an “amber top” on its institutional voting information service, which alerts investors to potential breaches of best UK corporate governance practice.