Garry Monk has resigned as Leeds manager, the club have confirmed.
His decision to leave the West Yorkshire club comes just a day after a new owner was announced.
Andrea Radrizzani completed his takeover of the club on Wednesday but less than 24 hours later they have been left with no manager.
Former Swansea boss Monk had a touchline bust-up with Town boss David Wagner during the last derby clash.
Radrizzani, a sports TV rights entrepreneur who co-founded media agency MP & Silva in 2004, began talks to invest in Leeds in August last year.
He appointed former Real Madrid director of strategy Ivan Bravo to the board at Elland Road in April and his takeover ends the stormy three-year reign of fellow countryman Cellino.
Cellino, 60, who took control at Elland Road in April 2014, sacked six head coaches before appointing Garry Monk last June and had been urged to sell by the majority of fans, who had grown weary of his off-field controversies and handling of the club.
The former Cagliari owner was banned by English football’s authorities three times during his tenure at Elland Road.
In February, Cellino announced he would bid to clear his name in the High Court despite an 18-month ban and £250,000 fine for breaching Football Association rules on players’ agents being reduced on appeal.
His FA ban and fine, imposed in December 2016 for breaching regulations over the sale of Ross McCormack to Fulham in 2014, was reduced to 12 months and £100,000 respectively.
In April 2014 an independent QC overturned the English Football League’s decision to disqualify Cellino due to a tax conviction and the Italian completed his takeover at Leeds having agreed a deal in the January to buy a 75 per cent stake from previous owner Gulf Finance House.
But Cellino was disqualified by the EFL for three months in December 2014 after an Italian court confirmed his conviction for tax evasion had been a dishonest act and in October 2015 he appealed against a further EFL ban for another tax conviction in Italy.
Leeds appeared on course to secure a play-off place under Monk this season, but a poor run of results in their last eight games saw them slip out of the top six.