According to reports, the board of ITV has been briefed on Allen's departure and will now attempt to find a successor to the ITV boss, who has headed up the network and was instrumental in the merger of Granada and Carlton Communications to form the single ITV, which was completed in January 2004.
Possible successors already touted for the chief executive position include: Stephen Carter, the former chief executive of Ofcom, who left the regulator at the end of last month; Dawn Airey, Sky's programming boss; Channel 4 chief executive Andy Duncan; and David Elstein, former chief executive of Five and current chairman of Sparrowhawk Media.
The move comes on the back of talks of a renewed approach to buy the broadcaster by Roger Parry, chairman of regional newspaper publisher Johnston Press.
Parry can not mount a bid for ITV until October after he was told to declare his intention to make a formal bid by the Takeover Panel in April or back away from the process. At the time, Parry said he had no intention of bidding for the broadcaster.
However, he is expected to renew his interest once the deadline expires. Reports suggest he wants to break the broadcaster into two separate companies, one containing production and the other controlling channels.
Parry is not the only potential bidder believed to be circling the troubled broadcaster, with reports stating that potential approaches could come from Lord Hollick, the former chief executive of United Business Media, who could be backed by private equity company KKR.
Greg Dyke, the former BBC director-general and managing director of LWT, may also make a renewed approach after failing to acquire the broadcaster in a £1.3bn bid, backed by investment bank Goldman Sachs, Apax and Blackstone, in March this year.
Allen has been criticised for the ITV network's falling ratings and under-performing programmes on ITV1, including 'Love Island' and daytime show 'This Morning', and also for allowing broadcaster's share price to fall.
ITV shares were up 2.2% this morning and are currently trading at 103.75p.
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