Panathinaikos forced to play behind closed doors
Angry supporters invaded the Olympic Stadium pitch on Saturday after the champions' 1-0 loss to promoted Olympiakos Volos and fans also attacked the VIP area before being ushered away by stewards and police.
The league announced that the Athens club would have to play two successive matches behind closed doors and pay a fine of 71,500 euros.
A club spokesman said an appeal from Panathinaikos could be possible but that no announcement regarding this would be made on Thursday.
The club has already been in trouble with the Super League's disciplinary committee this season, having been fined 96,000 euros last Thursday for previous disturbances.
Saturday's result left Jesualdo Ferreira's team five points adrift of leaders and arch-rivals Olympiakos Piraeus at the halfway point in the season, a situation which prompted club president Nikos Pateras to step down on Monday.