The confiscations by anti-mafia police represented the largest operation against the crime syndicate ever conducted in Italy, ANSA reported.
Seized were 43 companies or stakes in companies, 98 properties and seven vehicles, police said. In addition, 66 financial assets were confiscated, including bank accounts, credit cards and life insurance policies.
The confiscations took place in Sicily, Lombardy, Lazio and Calabria.
All the property and assets belonged to Vito Nicastri, whom Italian media described as a leading player in the clean energy industry, particularly wind and solar energy.
Investigators said the seizures, the latest in a "scorched earth" policy to drain the resources of fugitive crime boss Messina Denaro, "hit the gray area of Cosa Nostra."
Police charge Nicastri "maintained constant relations with members of Cosa Nostra" in three provinces that gave him "a prominent position in the south [of Italy.]."
Previous investigations have found "huge" involvement by Cosa Nostra in wind farms near Trapani, Denaro's alleged base of operations.
Nicastri, 57, was ordered into "special supervision" that requires him to regularly check in with police.