NEW YORK (Reuters) - The S&P 500 suffered its worst decline since November 7 on Monday in a sharp reversal from initial gains as elections in Italy stoked concerns that a divided parliament could disrupt the country's fiscal reforms and the euro zone's stability.

Based on the latest available data, the Dow Jones industrial average <.DJI> slid 216.40 points, or 1.55 percent, to end unofficially at 13,784.17. The Standard & Poor's 500 Index <.SPX> dropped 27.75 points, or 1.83 percent, to finish unofficially at 1,487.85. The Nasdaq Composite Index <.IXIC> lost 45.57 points, or 1.44 percent, to close unofficially at 3,116.25.

(Reporting by Caroline Valetkevitch; Editing by Jan Paschal)