The 55-year-old Scot has been under City pressure for some months to leave Granada owing to the part he played in the doomed ITV Digital venture.
Subsequent poor audience figures and torpid advertising revenue has meant that this pressure has not been alleviated to date.
His departure comes at a crucial time for Granada and ITV, with senior Granada sources keen to see the company merge with Carlton to create a single ITV company.
Morrison has ostensibly been offered an early retirement deal and his departure, some four months after the collapse of ITV Digital, is designed to distance him from the debacle for which only the former ITV chief executive, Stuart Prebble, has taken responsibility.
It is expected that Granada's executive chairman, Charles Allen, will take greater operational control of the company with a non-executive deputy chairman appointed to replace Morrison.
Morrison, who according to Granada's financial reports was paid £345,000 last year, was conspicuously absent from this year's Edinburgh Television Festival, fuelling speculation of his departure.
Morrison has been at Granada since 1974, joining as a journalist on World in Action and achieving some acclaim as a producer and director on films such as My Left Foot and Jack & Sarah.
Morrison was made the chief executive of Granada Media Group, comprising Granada's TV interests, in 1996.
The group subsequently demerged from the catering side of the business in 2000 but retained the Granada name.
At the time of the demerger Granada shares traded at 515p but following the various problems the company has encountered the share price has fallen to 91p.
A spokesman for Granada said: "We never comment on rumour. However, numerous sources are unanimous in saying that Morrison's departure is imminent.