Toulouse are in the relegation zone after suffering a 1-0 defeat at Lens on Saturday following an embarrassing 6-1 thrashing at home to Marseille.
President Olivier Sadran confirmed that former Toulouse defender Arribage has taken the helm, with Casanova's seven-year reign coming to an end on Monday.
Arribage, who was working as a scout for the club, will be assisted by Teddy Richert and Michael Debeve - also former Toulouse players.
The 43-year-old's first game in charge will be a home clash with high-flying Bordeaux on Saturday.
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