A group of Italian investors withdrew a bid on Thursday to buy bankrupt Italian airline Alitalia, after six of Alitalia's nine unions failed to back a rescue plan.

Italian media reported that the move edged Italy's national carrier ever closer to failure. Italian Labour Minister Maurizio Sacconi said in a statement that the failure put Alitalia "on the road" to liquidation.

The investors' withdrawal was welcomed among Alitalia workers gathered in a spontaneous protest at Rome airport.

An Alitalia air attendant expressed his worries.

"As a couple doing the same work, my wife is temporary, I am permanent. I've been working here for 14 years. Our problem is that if such a contract is enforced she will be fired and I will have a terribly reduced salary."

It was the third attempt to sell the airline that has failed since the previous government decided to privatize the airline nearly two years ago.

Paolo Maras, leader of flight attendants' union SDL believed there would be a solution.

"We believe we cannot lose this thing (Alitalia) which belongs to the whole country, therefore we believe a solution must be found. This is why we are still optimistic, even in this dramatic situation."

But the investors stuck to their position that the time for talking was over in that the cash situation is increasing pressure on the airline's operations.

The airline has been losing 2 million euros, or around 3 million US dollars a day, and analysts have said a loan of 300 million euros approved by the last government to keep the airline flying won't last.

Italy's civil aviation authority said in a statement that it would meet with Alitalia officials on Monday to verify whether the airline still met licensing requirements to fly.