Broadcaster ITV is likely to appoint an external candidate to take over from executive chairman Michael Grade, according to press reports.The Times writes that Simon Fox, the chief executive of HMV, and Pascal Cagni, Apple's most senior executive in Europe, are now the frontrunners to take the top position at the media group.Of the two internal candidates, commercial director Rupert Howell is telling friends that he is no longer in the running, the paper reports, while chief operating officer John Cresswell is now only considered to be a 'fall-back option.' Guillaume de Posch, the former chief executive and chairman of German media group ProSiebenSat.1, and Tony Ball, the former head of BSkyB, have also been mentioned as potential suitors for the job.ITV began its formal search for a new chief executive in April after Grade announced he is to relinquish his executive responsibilities by the end of the year to become non-executive chairman.