Shares in Fiat (FIA.MI) fell more than 8.5 percent on Wednesday to their lowest level this year, with traders citing concerns that investors who voted against the Italian carmaker’s merger with Chrysler would exercise their right to sell the stock, potentially jeopardizing the tie-up. The losses wiped out all the gains the carmaker has made since announcing on Jan. 1 that it would buy out the shares in its U.S. unit Chrysler it did not yet own, cementing the creation of the world’s seventh largest auto group.