MADRID - Atletico Madrid will have to play Wednesday's Champions League match against PSV Eindhoven behind closed doors after sport's court of arbitration (CAS) partially upheld a punishment handed down by UEFA for crowd trouble. CAS ruled that the sanction should stand because of "serious security breaches" during a Champions League match against Olympique Marseille in Madrid on October 1. However, it overturned a suspended sanction of a second match behind closed doors and cut a UEFA fine of 150,000 euros ($187,900) by half because it said there was not enough evidence to support allegations Atletico fans made racist chants. In its original ruling, UEFA said failures in Atletico's organisation had prompted confrontations between Marseille fans and police and ordered them to play their following two European fixtures at least 300km outside Madrid, with a home stadium ban for a third game if there was further trouble. Atletico appealed and the sanction was cut to one match played behind closed doors together with a suspended sentence of one more game played without fans. The fine was confirmed. The club protested its innocence of all charges and took its case to CAS which ruled after a hearing on Wednesday. SECURITY BREACHES "Having examined the arguments and evidence submitted by the parties, the CAS Panel, in line with UEFA, concluded that Atletico Madrid committed several serious security breaches during the match against Olympique Marseille which allowed the incidents to occur," the court said in a statement. CAS said the fine had been reduced by half "in light of the fact that the racist acts alleged by UEFA could not be established with certainty". Atletico noted in a statement on Thursday that the original punishment had been "considerably reduced". It said CAS had backed its assertion "100 percent" that there had not been any racist chanting. Atletico defender Mariano Pernia said it was "unbelievable" that they would have to play the PSV match in an empty stadium. "It's unthinkable that we'll be playing in our stadium but without our supporters," he said on the club's website www.clubatleticodemadrid.com). "It will be incredible because that is one of the things that drives us on the most." However, Olympique Marseille chairman Pape Diouf was disappointed the original punishment had been diluted. "Week after week, sanctions become milder. I am deeply disappointed. It encourages extreme behaviour...," he was quoted as saying on his club's website (www.om.net). UEFA referred a request for comment to the CAS statement and said it had nothing to add at this stage.