Fassone backs under-fire Montella

"Vincenzo is staying with us. When you change this much, as we did, you need time," said Fassone.

Milan overhauled their squad in the close season, spending 230 million euros ($270 million) on new signings following the takeover of the club by Chinese businessman Li Yonghong.

He already paid 740 million euros to buy the club last April.

But despite the heavy investment, Milan have failed to find their rhythm on the pitch yet, with Montella's side dropping three places to tenth after their latest defeat -- 12 points behind leaders Napoli and ten adrift of second-placed Inter.

"AC Milan should not be in that position and we have to climb back," insisted Fassone, appointed managing director after Li's Rossoneri Sport Investment bought the club from former Italian Prime Minister Silvio Berlusconi.

"We are starting to see the first positive signs, but Montella will still have time to continue his work," continued Fassone.

"Things will change eventually."

Mauro Icardi converted a late penalty to complete a hat-trick that gave Inter a 3-2 win in front of a capacity crowd of 80,000 at the San Siro.

The gate receipts for Sunday's derby clash hit a new Italian football record of 4.8 million euros ($5.6m) -- over a million euros more than the previous record set when Inter met Juventus in October 2015.

"Derbies are always incredible matches, this time we made a mistake at the end and we have to see their fans celebrate," said Fassone.

"I am sure the next derby will be a good one for our supporters.

"The second half was played brilliantly, it looked like a completely different game. We have to start from here, from this performance in the second half."

Montella's side next host AEK Athens in Europa League action on Thursday, having made a strong start in Europe's second-tier competition.

"We want to do well in the Europa League no matter what we do in the league," said Fassone.

"Europe is our home and we want to make it as far as possible in the Europa League. Thursday we'll play with the right spirit."

Montella warned: "A false start can happen. But now it's time to work hard to bounce back and climb the table".