Sensex opened at 74,806.49, down 394.36 points or 0.52 per cent, while Nifty began the session at 23,457.25, slipping 160.75 points or 0.68 per cent. Later in the morning trade, the 30-share index declined as much as 671 points or 0.89 per cent to hit an intraday low of 74,529. Similarly, the Nifty fell 220 points or 0.93 per cent to 23,397.