Bastia must forfeit the game against Lyon that was abandoned following crowd violence, the French Football League (LFP) disciplinary commission has ruled.
The Ligue 1 match on April 16 was abandoned at half-time after home fans twice invaded the pitch and attacked visiting players.
Bastia must also play three home games behind closed doors on neutral territory -- one of which they have already played.
They will not be allowed any away fans in their next three matches on the road, which include trips to Paris Saint-Germain and Marseille.
However, the LFP did not inflict a points deduction or impose a scoreline for the forfeited game, meaning Bastia remain two points from safety with a better goal difference than two of their four rivals in the battle against relegation.
Bastia head of security Anthony Agostini, involved in a melee with Lyon goalkeeper Anthony Lopes, was given a six-month ban from carrying out match duties with two months of that suspended.
Bastia president Pierre-Marie Geronimi told footmercato.net his club would contest their punishment.
"For the moment, we're going to settle for saying we're immediately going to appeal this decision and that the club will fight to the end on and off the pitch to save its place in Ligue 1," he said.
The three points awarded to Lyon mean they are four points clear of Bordeaux in fourth place, which would give them a spot in next season's Europa League.