Italian carrier Alitalia has cancelled 106 flights because of a four-hour strike by air traffic controllers.
It has rescheduled more than 200 flights for Wednesday.
The airline said 64 of the flights it has cancelled on Tuesday are domestic and 42 international.
Some 13,000 passengers are expected to be affected by the disruptions.
The strike is scheduled to start later this morning, said the national air traffic controllers' association, ENAV.
The air traffic controllers are in contract disputes.