Stock markets fell sharply on Thursday, with the BSE benchmark Sensex plunging 351 points to 19,183. Markets fell onbelow-expectation quarterly results posted by software major Infosys and heavy selling in banking scrips on fears of interest rate hike. Erasing Wednesday's gain of 338 points, the Sensex settled 351 points at 19,183 points. The index dropped 400 points in the intra-day trade and could not recover much. The National Stock Exchange's wide-based Nifty nosedived by 111 points to settle at 5752 points.