The Acun Medya Group took over Hull City less than a week ago.
After guiding the club back to the Championship last season, the 41-year-old was relieved of his duties by the club.
He leaves despite the club being 10 points clear of the drop zone.
Chairman and owner Acun Ilicali said that these matters are never easy.
Grant has always been professional and focused on the team, and will always be a friend of the Tigers. Grant will be successful in his next challenge.
The time is right for change and for me to start to build, in what I believe will be an incredibly exciting time for the club.
As the Acun Medya Group prepares to bring in a new coaching set-up, the assistant boss has also left the club.
The first season at Hull seemed to be a failure after the January sales of two key players, with the club falling from mid-table to League One.
After leading Hull to the League One title the following year, the Northern Irishman returned their second-tier status, and they have been steady this season.
Ilicali said that he has a philosophy and a belief that his project should start as he wants it to.
I understand the timing may look odd, after two good wins, but I wouldn't be fair or honest if I waited for a defeat to change manager.
That benefits no one. I will be transparent with you. Our new head coach will be announced very soon.
The next Championship fixture is at Hull on Saturday.
David Burns is a commentator.
I am aware that some people might be thinking: Barmy! The team has just beaten two of the top three in the Championship.
The decision was made a few weeks ago by the new owner Acun Ilicali as he moved towards the takeover of the club. If you asked the majority of fans two weeks ago if they wanted to keep him, most would have said they would help him pack his bags.
The new owner wanted his own man and ex-Rangers and Ajax player Shota Arveladze is expected to be announced as the new boss before the weekend match.
How will he be judged in the history of the Tigers? When they crashed out of the Championship with one win in 20 the season before, many had made their mind up about him, but last season he delivered their first title win in 55 years.
A lot of people were thinking about him because of his inflexibility and refusal to recognize the possibilities of being demoted.
He deserves a lot of credit for last season's revival and digging them out of the bottom two this season, but he will also be seen as the man of the Allams, and I think that counts against him.
All Rights Reserved © 2024
