Anti-Mafia police in Italy on Wednesday seized hundreds of millions of euros in assets from Sicilian "supermarket king" Sebastiano Scuto after an appeal court convicted him of Mafia ties.

The police said a total of 409 properties were seized along with the assets of 48 companies, all linked to Scuto and his immediate family.

The assets are being seized but not formally confiscated, which would happen only if Scuto's conviction is upheld by Italy's highest court.

Scuto's company Aligrup has 1,600 employees and prosecutors said existing agreements with the unions would be respected and that their job security could even be improved by legal action.

An appeals court in the Mafia-ridden Sicilian city of Catania last month convicted Scuto to 12 years in prison for "association with the Mafia".

Scuto had been acquitted at his first trial, where his lawyers argued he had been forced to pay extortion, but the prosecution had appealed.

Investigators said Scuto had developed close ties with a Mafia clan in Palermo and had laundered their money through his businesses.

The asset seizures on Wednesday were carried out in Salerno in southern Italy, Reggio Emilia in the centre and Monza and Milan in the north.