Rome - A wildcat strike by Alitalia employees forced Tuesday the cancellation of at least 20 flights at Rome's Fiumicino airport and further disruptions at airports in Milan, Naples and Venice.

The 24-hour walkout by pilots, flight attendants and ground staff is to protest what they say is a breach in an agreement with labour unions by a private consortium, CAI, which has offered to buy Alitalia's state-owned controlling state.

Italian Transport Minister Altero Matteoli has branded as illegal the strike, which is not supported by most of the unions representing Alitalia's 17,000 employees.

Matteoli warned striking workers could face legal action if they pressed on with threats to stage new stoppages in the coming days.

Alitalia, which is facing debts of more then 1.2 billion euros (1.5 billion dollars), saw bookings decline by 30 per cent in September compared to the same period in 2007, according to Milan daily Corriere della Sera. (dpa)