Alitalia's administrators said they had no preferred option between Delta Air Lines and Lufthansa, the two groups talking with rail operator Ferrovie dello Stato about a rescue for the troubled Italian carrier.

Ferrovie, which is leading a state-orchestrated effort to rescue Alitalia, will have to choose between the two foreign carriers in the next weeks as the financial performance of Alitalia was deteriorating, the administrators said.

"We do not have any preference about the industrial partner for Alitalia, we are unbiased," Daniele Discepolo, one of the three administrators in charge of the airline told a parliamentary hearing.

Delta and Lufthansa belong to rival respective airline alliances and are both interested in the lucrative Italian market, one of the world's top tourism destinations which is seeing good growth in foreign visitors.

Lufthansa wrote to Ferrovie recently offering a commercial partnership with Alitalia and saying it could take a stake in the carrier under certain conditions to be agreed with other partners.

The German carrier, however, has so far refrained from indicating precisely how much it was prepared to pay and under what conditions. In the letter Lufthansa only said it could invest more than Delta, which, so far, has committed around EUR 100 million (US$111 million) for Alitalia.

Discepolo and fellow administrators Enrico Laghi and Stefano Paleari said the government's planned grant of a fresh 400 million euros bridge loan was needed to keep Alitalia's airplanes flying until the rescue was successfully finalised.

The state has already granted a 900 million euro loan for the carrier and analysts calculate that Italian taxpayers have spent more than 9 billion euros to support Alitalia, which has undergone two previous failed rescue attempts.

Paleari said Alitalia's earnings before interest, tax, depreciation and amortisation (EBITDA) were negative to the tune of 164 million euros in the first half of this year, worsening from a 124 million euro loss in the same period last year partly due to higher fuel costs.