Alitalia was the major share holder with the 90% of the airline's capital and the remaining 10% held from the state holding company IRI.

ATI started operations on 2 June 1964 from its headquarters and main hub at the Naples Capodichino airport with a pair of Fokker F27s aircraft, of which a total of 13 were delivered by 1969; the same year the first 4 Douglas DC-9-32s joined the fleet.

Characteristic of ATI in the years that followed were the east-west connections in southern Italy and the Adriatic route from Trieste to Brindisi with some stops.

On 20 March 1981, Aermediterranea was formed as a joint-venture between Alitalia and ATI to replace the private airline Itavia on the Italian internal scene.

After the revocation of the air operator's certificate of Itavia, the flight crew was transferred to Aermediterranea which was merged into ATI in March 1985.