Mediation between Fiat and General Motors may have ended without a deal, but the Italian group is still hoping it can persuade the US auto giant to buy its ailing car division.GM wants out of the deal and launched a mediation process in mid-December which expired this week. Investors had expected GM to pay Fiat about 1.8 billion euros to scrap its sale option and avoid a lengthy court battle. But a Fiat spokesman said the communication channels were still open. The company insists the sale option remains valid and can be exercised any time from till mid-2010. Fiat shares were boosted by the news. The Italian government is watching from the sidelines. Auto unions and media have suggested the government could take a stake in the carmaker if it were to split off from the rest of the Fiat group. But ministers are opposed. FIAT officials say its partnership with GM is stopping it forging links with other carmakers.