Neil Lennon has parted company with Scottish Premiership champions Celtic, his agent has said.
Martin Reilly - who represents the Northern Irishman - said that after four years and three title wins, the former club captain had decided he wanted to take on a fresh challenge.
He told Press Association Sport: "Four years is a good spell to be manager of a club like Celtic but now Neil wants to look ahead to the next chapter of his career."
BBC Scotland quoted Lennon as saying: "I have parted company with Celtic. I can't thank Peter Lawwell and the board enough for their backing and support.
"I wish the fans and the club all the very best for the future"
"The club are in a very strong position and I wish the fans and the club all the very best for the future."
The 42-year-old replaced Tony Mowbray in 2010 and as well as leading the club to three successive Scottish Premiership successes, he has also helped the Hoops claim two Scottish Cup wins and masterminded their run to the last 16 of last season's Champions League.
That European campaign also included the famous Parkhead win over Barcelona and former Leicester midfielder Lennon is now expected to continue his career in England.
But despite being linked with the vacant managerial positions at Norwich and West Brom, Reilly insists his client has not agreed to any job offer yet.
He added: "He has nothing lined up. He just feels now is the time to move on to the next challenge."