While no official confirmation has been forthcoming from PSG, who are top of Ligue 1 heading into the winter break, reports from France suggest his tenure is at an end.
UNECATEF released a statement to L'Equipe, reading: "The UNECATEF formally condemns the dismissal of Antoine Kombouare and his deputies by the management of PSG.
"All coaches, all technicians in France can only be indignant about the fate of one of them. Why blame him? For not being glamorous enough? Not good enough?
"Whatever the reasons, nothing can justify or excuse the brutal dismissal.
"UNECATEF will be with Antoine Kombouare as long and as firmly as is necessary."
The 48-year-old manager been with PSG since May 2009 following a five-year spell at Valenciennes but has seen his position come under intense scrutiny is recent weeks, with the likes of Carlo Ancelotti and Frank Rijkaard being linked with the role.
The club failed to make it through the group stages of the Europa League but on Wednesday night defeated St Etienne to go three points clear of Montpellier at the top of the Ligue 1 table.