The Indian equity benchmarks edged lower on Thursday ahead of weekly expiry of index futures and option contracts due later today amid weak cues from other Asian markets. The Sensex fell as much as 546 points and Nifty 50 index touched an intraday low of 17,091. HDFC Bank, Kotak Mahindra Bank, ICICI Bank, HDFC and Titan were among the top drags on the Sensex.