Fiorentina are the latest Italian club to move into foreign ownership.
The club says their board has resigned after being informed by the Della Valle family that a sale process is under way.
Montella receives the ban after insulting the referees and indirectly causing harm to a steward after punching an advertising hoarding.
The 21-year-old's performances have been slightly offset by Fiorentina's leaky defence and they go into Sunday's Serie A match at home to Lazio in 10th place.
Federico Chiesa scores a stunning solo goal and sets up the late equaliser for Luis Muriel after Atalanta, who knocked out title holders Juventus in the previous round.
Inter Milan plays without Mauro Icardi again, who has not featured since being stripped of the club captaincy but his presence was still felt at the Artemio Franchi.
Alessandro Florenzi's equaliser gave AS Roma a 1-1 draw against Fiorentina.
Fiorentina coach Stefano Pioli and his Atalanta counterpart Gian Piero Gasperini clashed after the final whistle over a hotly-disputed penalty which set up a 2-0 win for Fiorentina.
The last week has seen them beat Tottenham Hotspur in the Champions League and Sampdoria in Serie A, both with stoppage time goals.
Sampdoria's Gianluca Caprari scored their equalising goal.
Serie A said it had postponed Genoa’s match at AC Milan and Sampdoria’s game at home to Fiorentina following requests made by the two clubs “as a consequence of the tragedy which has struck the city of Genoa.”
Lucas Pérez and Carlos Sánchez were signed from Arsenal and Fiorentina respectively.
Napoli's title hopes looked in tatters on Sunday after a shock 3-0 defeat at Fiorentina, complete with an early sending-off for Kalidou Koulibaly and a hat-trick from Giovanni Simeone, edged Juventus closer to a seventh successive Serie A title.
Games postponed are Atalanta v Sampdoria, Benevento v Verona, Chievo v Sassuolo, Torino v Crotone and AC Milan v Inter Milan.