"We will call for play to be stopped for 10 minutes when these things happen and announcements to be made in the stadium," Platini told a news conference in Rome. "If it continues the match will be stopped. Courage is needed when there is racism in the stands. That's UEFA's mission."
Racist abuse is not uncommon in Italian football and small fines are usually handed out. However, the seriousness of Saturday's incidents prompted the authorities to come down heavily on Juve.
"It is a difficult moment for the Italian soccer federation. It has taken its responsibility," added ex-Juve player Platini.
"The Italian system already gives the authorities the power to suspend the game in the case of banners that incite racial discrimination," he said.
"We'll reinforce this, naturally while staying attentive and finding a balance for the security requirements of the public."
The 18-year-old Balotelli scored Inter's opener in the top-of-the-table clash and was subjected to chants of "a black Italian does not exist" from sections of the crowd in Turin.
Inter Milan president Massimo Moratti said he would have pulled his team off if he had been at Turin's Stadio Olimpico.
Platini was in Rome to hand the Champions League trophy to the city ahead of the final here on May 27. UEFA has stuck with its decision to host the final in Rome despite Italian soccer's problems with racism and hooliganism.
