Economy Minister Daniele Franco told a news conference neither of the two rival bids currently fully met the government's goals for the privatisation of the company.
Shipping group MSC and Germany's Lufthansa are facing a rival bid made by a consortium comprising U.S. private equity fund Certares, Air France-KLM and Delta Air Lines Inc.
Prime Minister Mario Draghi, who resigned last month and will remain in a caretaker position until a new government is formed after next month's election, told reporters he wants his administration to complete the sale procedure.
(Reporting by Angelo Amante and Giuseppe Fonte; Editing by Keith Weir)