Fresh buying in FMCG, banking and metal stocks helped the index rebound into the positive zone, the index touched a high of 16,545 - up 327 points from day's low (16,218) in late noon deals.
The Sensex finally ended (provisional) with a gain of 275 points at 16,551.
The market breadth was neutral - out of 2,756 stocks traded, 1,333 advanced, 1,335 declined and 88 were unchanged today.
The NSE Nifty moved up 58 points to close (provisional) at 4,918.