ITV chief executive Charles Allen has announced his resignation, ending days of speculation about his future.
Mr Allen will leave his post in October
Finance director John Cresswell will take over as interim chief executive on 1 October while ITV continues its search for a permanent replacement.
Earlier this week, it emerged that Mr Allen was negotiating the final terms for his departure.
ITV has been suffering in recent months in the face of low viewing figures and falling advertising revenues.
Rising competition from digital TV stations has resulted in fragmented audience, a factor seen as partially responsible for the group's woes.
Constraints on advertising pricing under a complex contract rights renewal scheme, negotiated with regulators by Mr Allen, had also left Mr Allen under pressure.
The deal limits the amount of money the firm can demand from advertisers, making it even more difficult for ITV to make money.
"The role of the chief executive is to take the bullets in the creative community when it doesn't go well and step out of the light when things go well," Mr Allen said.
"That's how you'll get people to take risks and this game is all about taking risks. We never get it right all the time," Mr Allen said.
The group's chairman, Sir Peter Burt, described Mr Allen's record during his two-year tenure as an "excellent job".
"The board of ITV owes its thanks to Charles for his success in creating a single ITV company from the federal structure that he inherited and for preparing the company for television in the digital age," chairman Sir Peter Burt said.
Among the names touted as possible replacements for Mr Allen, Channel Four chief executive Andy Duncan is the one experts favour to win the post, if he wants it.
Other names in the ring are Sky's Dawn Airey and Stephen Carter - former head of media watchdog Ofcom.
But analysts have hinted that the recruitment process could prove difficult as the firm is widely viewed as a takeover target.
Earlier this year it rebuffed an approach from a group led by former BBC chief Greg Dyke, while rumours of a possible bid approach gave its shares a lift last week.
The commercial broadcaster's board met on Monday to discuss Mr Allen's departure, days ahead of the group's half-year results on Wednesday.
According to reports, Mr Allen will receive his contractual entitlement to a year's salary, as well as "augmentation" of his pension.
Mr Allen earned a total of £1.85m last year, while his pension pot was worth £8.5m.
Shares in the firm ended the day 3.25 pence, or 3.2%, lower at 98.25p.