As well as leaving Juventus, Agnelli also said he would step down from his board roles at carmaker Stellantis and Exor, the Agnelli family holding company which controls the football club.
Prosecutors in Turin have requested that Agnelli, 11 other people and the club stand trial over allegations of false accounting.
Juventus, the most successful club in Italian football history, have repeatedly denied any wrongdoing.
Agnelli has chaired Juve since 2010 and was one of the architects of a failed attempt to set up a breakaway European Super League together with other top clubs in 2021.
“I believed and still believe that European football needs structural reforms to tackle the future,” he said.
“Otherwise we are heading for inexorable decline for football in favour of a dominant league, the Premier League, which over a few years will attract all the European talent and marginalise the others,” he added.
Agnelli handed his successor, accountant Gianluca Ferrero, a black and white Juventus shirt, with Ferrero’s name and No 1 on the back.
“We’ll work to give Juventus a future which matches up to its glorious past,” Ferrero told reporters.
Family business
Agnelli is part of the family that founded carmaker Fiat, now part of the Stellantis group, and which has owned Juventus for a century.
He said his decision to step down from the other boards was made in agreement with Exor boss John Elkann, who is a cousin, and Stellantis CEO Carlos Tavares.
“My desire is to want to face the future with a clean slate, to have freedom to think and act. And for this reason it feels like a duty to take a step back from the boards,” he said.
Agnelli retains his role as board member at Giovanni Agnelli BV, Exor’s controlling shareholder, which groups all descendants of Fiat founder Giovanni Agnelli.
The new Juventus chairman Ferrero will head new a slimmed-down, five-member board which will immediately have to address the club’s legal troubles.
“We think we have got the experience, knowledge and determination to defend the club in all contexts, criminal, civil and sporting ones,” Ferrero said.
A hearing is scheduled for Friday before sporting authorities on Juventus transfer dealings, which could overturn a previously ruling that cleared it of wrongdoing.
The club is expected to face only a fine if found guilty in that case.
However, football authorities are now looking into all documents collected by general prosecutors in Turin, bringing the risk of new cases with potentially heavier sanctions.
The new board will also have to restore the loss-making club’s financial fortunes, hit by rising costs linked to players’ salaries and the coronavirus pandemic.
New CEO Maurizio Scanavino, the current head of Gedi, the media group owned by Exor, today said Juventus targets and ambitions remained unchanged, both on and off the pitch.
“Our main target will be to expand our fan base, aiming at young people and abroad,” Scanavino said.