Italy joins the other big-five leagues in England, Spain, Germany and France whose members opposed the ECA plan.
The plan seeks guarantees for 24 of 32 Champions League group teams to return the following season. That would reduce end-of-season intrigue in domestic leagues.
According to the 15 Italian sides, the plans – which consist of promotion and relegation in European competitions – could lead to a decrease of as much as 35 percent in Serie A revenues.
However, Juve voted the document down, given their President Andrea Agnelli is also the head of the ECA and is pushing for a Super Champions League.
“Even if his vision turns out to be the right one to protect European football, he was wrong in terms of method and communication,” said Lega Serie A President Gaetano Micciche, in a jibe at UEFA chief Aleksander Ceferin.