Embattled broadcaster ITV's hunt for a new chairman has suffered another blow as both of the leading contenders ruled themselves out.In a statement, ITV said that former Reed Elsevier boss Sir Crispin Davis and former BMI boss Sir Michael Bishop have both confirmed to the nominations committee of the board that they are not candidates.Reports last week had suggested Sir Crispin Davies had declined, but former Channel 4 chairman Sir Michael Bishop was still being tipped over the weekend as the favourite for the post.Other knights of the realm said to be in the running for the chairman post are Sir Christopher Gent, chairman of drugs group GlaxoSmithKline, and Sir Christopher Bland, former chairman of telecoms firm BT; Bland is also a former chairman of the board of governors of the BBC.One of the first roles of the new chairman will be to agree on a new chief executive officer (CEO) for the struggling TV group. In the meantime, John Cresswell, currently Chief Operating Officer, will assume the role of interim chief executive and help to find a permanent replacement. Cresswell was previously interim chief executive back in 2006 and will resume the role when the new chairman arrives. This time, however, he will quit the company when a new CEO is appointed.The reappointment of Cresswell as an interim measure is another chapter in the prolonged and fraught process of replacing Sir Michael Grade, who previously combined the chairman and CEO roles. Simon Fox, chief executive of entertainment media retailer HMV, was thought to be the ITV board's first choice for the CEO position but he chose to stay with HMV.Pascal Cagni, head of European operations at Apple, the iPhone maker, was then mentioned as a possible candidate but it was former BSkyB chief executive Tony Ball who looked odds on to get the gig until negotiations between the two parties ended abruptly towards the end of September. ITV reportedly balked at Ball's demand for a five-year pay package worth more than £25m plus a potential additional £42m in incentive payments.