Lucien Favre has been "relieved of his duties" as coach of French Ligue 1 side Nice, a source close to the Ineos-owned club told AFP on Monday.
The 65-year-old Swiss, who returned to Nice at the start of the season following a first spell between 2016 and 2018, is expected to be replaced by his assistant Didier Digard.
Nice are currently 11th in Ligue 1, already 12 points adrift of the European places before the halfway stage in the season has been reached.
On Saturday, they were knocked out of the French Cup at the first hurdle, losing 1-0 to third-tier side Le Puy.
Such disappointing form is despite considerable investment in the Cote d'Azur side by Ineos, the group chaired by Monaco-based British petrochemicals billionaire Jim Ratcliffe who bought the club in 2019.
Nice finished fifth in Ligue 1 last season and lost the French Cup final to Nantes, before coach Christophe Galtier departed to take over at Paris Saint-Germain.
Digard, a former Nice captain who was already on the coaching staff, is set to make his debut in charge for Wednesday's league game against Montpellier.