Blackburn Rovers manager Paul Lambert will leave the Championship club at the end of the season.
The 46-year-old Scot joined Blackburn in November, but has activated a clause in his contract to leave after their final game against Reading on 7 May.
At the start of the April, former Aston Villa boss Lambert stated he would 'wait and see' about his future after talks with the club's owners Venky's.
He has won 10 of his 31 games in charge as Rovers sit 18th in the league.
Lambert has been quickly installed as odds-on favourite with several bookmakers to take over at Celtic, where he spent seven seasons as a player.
"I would like to place on record my thanks to the owners and especially the players, staff and fans for the tremendous backing and support I have received since I arrived," he told the club website.
|Recent Blackburn managers|
|2008 - Paul Ince||2012 - Henning Berg|
|2008-10 - Sam Allardyce||2013 - Michael Appleton|
|2010-12 - Steve Kean||2013-15 - Gary Bowyer|
|2015-16 - Paul Lambert|
"It's a brilliant club, with great people, and I wish it every success in the future. For now, I remain fully focused and determined to try to win the final two games of the season starting this Saturday against Rotherham."
Blackburn say the search for a new manager will begin 'with immediate effect'.
After replacing former boss Gary Bowyer, Lambert steered the club to a season-high position of 11th in the Championship table in December but they have struggled for form since.
Last month debts of £102.4m were revealed by Venky's, run by the Rao family that owns the club, who are based in India.
Blackburn are the sixth club he has managed, following spells at Livingston, Wycombe, Colchester, Norwich and Aston Villa.
Analysis - Andy Bayes, BBC Radio Lancashire
"Paul Lambert deciding to leave is no surprise.
"Over recent weeks he has grown increasingly frustrated at the lack of communication from the owners in India, with regards his plans for next season.
"His departure next month will leave Blackburn Rovers without a manager, chairman, chief executive or managing director. A situation that can not continue going forward."