Andrea Della Valle has stepped down as president of Fiorentina with immediate effect while also indicating the club, owned by his brother Diego, will be sold if new owners can be found.
"If there is someone else more suited to taking this project on, they should come forward now and if there are necessary guarantees, we are ready to put the club in his hands, if this is what is needed," Andrea said in a resignation letter posted on the club website.
Vice president Mario Cognigni will take temporary charge. The announcement was widely expected but Della Valle was coy about the reasons for his departure. "For some months I have strongly warned that there was no longer the necessary harmony regarding our project," he said.
Andrea faced criticism as president from the Viola fans for the club's lacklustre transfer activity this summer. Fiorentina sold Brazilian star Felipe Melo to Juventus, a move which angered the supporters, who were also displeased at them loaning Papa Waigo to Southampton.
Media speculation has also blamed his wish to spend more time in the family's luxury goods business, including Tod's. The Della Valles have dragged Fiorentina back up the Italian league after they were forced to re-form in the fourth tier.
Just two years later Fiorentina returned to Serie A and although involved in the 2006 Italian match-fixing scandal, the club have thrived and are again in the Champions League.
Despite the upheaval, Fiorentina are committed to funding a new stadium after talks with Florence council. The "Cittadella Viola" plan envisages not just a new stadium but an area of the city devoted to the club. Like most Italian sides, Fiorentina rent the ageing Stadio Franchi from the city.
"We would like to make clear to everyone that the Cittadella Viola is not a present from the City of Florence to Fiorentina," a statement said. By not owning their own stadiums, Italian clubs have lost out on revenue compared to English and Spanish sides and have suffered in European competition as a result.
Juventus are the first Serie A club to build their own stadium, with completion due in 2011. AS Roma will hold a news conference on Tuesday to announce plans for a new ground.