Balotelli, himself, has been fined 10,000 euros for an "insulting gesture" towards Inter fans at the end of the 1-1 draw.
Italian authorities have long been criticised by anti-racism campaigners for not cracking down hard enough on discrimination in sport and more displeasure may follow at Inter's relatively small fine coupled with a warning from the commissioner over future incidents.
The fine was not just for the Balotelli abuse but also for racism towards Milan's fellow former Inter player Sulley Muntari as well as offensive banners and fans' use of a laser aimed at players' eyes.
The 22-year-old Balotelli raised a finger to his lips when fans of Inter - where he had made his name before moving to England's Manchester City - made monkey calls and waved inflatable bananas at the San Siro.
Balotelli, Italy's most prominent black player, has been the biggest target of racist abuse from the stands and reports said part of his motivation for moving to City in 2010 was a desire to escape the insults.
Juventus were forced to play a home game behind closed doors in 2009 after fans racially abused the Italy international striker by singing "a black Italian does not exist".
He returned to Italy in January with Inter's biggest rivals Milan but any hopes that Inter fans would forgive him or, at least not racially abuse him, were soon dashed.
The Serie A statement said the abuse started "in the 11th minute of the first half" and continued "in the 11th, 15th, 16th and 19th minutes of the second half".
Italy had appeared to have finally got to grips with its football racism problem in January when Milan's Kevin-Prince Boateng stormed off the field in a friendly against lower league side Pro Patria following abuse from the stands.
The encounter was abandoned, Boateng was praised across the Italian and world game while Pro Patria were ordered to play their next home match in an empty stadium.
Italian referees were reminded of their powers to stop games after racist abuse but that did not happen on Sunday, with the insults only picked up on by the media once the match was over.
"Super Mario's black night," ran Monday's headline in Tuttosport daily, whose commentary concentrated more on the fact that this was the first game in which the player had not scored since transferring to Milan.
With Italy's election looking deadlocked, there seems little chance of a quick change to a law which meant that Balotelli, born in Italy to Ghanaian parents and adopted by Italians, could not get Italian nationality until he was 18.
