ROME (Reuters) - Italy has so far collected no revenues from a contested windfall tax on banks it introduced last year, Economy Minister Giancarlo Giorgetti said on Wednesday.

The government last year revisited a 40% tax on banks' net interest margin (NIM) it had introduced in August, giving lenders the option of boosting reserves instead of paying the levy.

"No payments are currently reported to have been received," Giorgetti said.

(Reporting by Giuseppe Fonte, editing by Alvise Armellini)