Italian civil aviation regulator ENAC has restored full operating licences of struggling Alitalia and its CityLiner subsidiary.
Alitalia is undergoing a sale process and is conducting business under extraordinary administration.
ENAC says it has restored the air transport operating licences, and withdrawn provisional licences for the carriers, following measures taken by the administrators.
It says the administrators have "pledged to ensure regular continuity of the business activity" while dealing with Alitalia's sale.
The Italian ministry of economic development authorised the procedure for selling Alitalia on 28 July.
ENAC says it will continue to monitor the airlines as required under European legislation.