Major companies Tuesday ruled out involvement in a new rescue of Alitalia, complicating a plan led by Rome in which state-controlled railway Ferrovie dello Stato (FS) will bid for the airline this week and bring in partners. FS is due to present an offer for the whole of Alitalia Wednesday subject to a series of conditions. FS's offer would only be a "transitional phase", a source close to the deal said. The source added the deal would be completed in 2 separate steps, with FS picking up Alitalia on set conditions and then, at a later stage, being joined by an Italian partner and an international one, from the airline sector. The source added there was very little visibility on next steps, and it was not clear which partners would join FS. "The situation is very messy," the source said. <br/>