Rome, February 25 - Concerns that ex-premier Silvio Berlusconi might come out of the Italian election with renewed authority weighed heavily on Wall Street Monday. The Dow Jones shed 0.10% to close trading at 13,988.07 points, the S&P 500 fell by 0.03% to 1,515.12, while the Nasdaq rose by 0.15% to 3,166.90 amid investors' concerns over the outcome of the Italian general vote held Sunday and Monday. While early exit polls showed the center left with a strong lead in both houses of Parliament, later results suggested the Senate might still be up for grabs. With Berlusconi's center right coalition a close second, investors began to fear for Italy's economy as well as the effects of a Berlusconi government on other countries tightly linked together in the eurozone. During the election campaign Berlusconi - who was forced out of government in November 2011 when Italy's bond yields were soaring so high they threatened the entire eurozone economy - pledged to undo many of the austerity measures of his replacement, caretaker Premier Mario Monti. The market "is starting to assess the risk that Berlusconi may abandon some austerity measures that have given Italy's credibility," Dave Lutz, an analyst at Stifel, Nicolaus & Co, told the Wall Street Journal.