The Sensex is now down 494 points at 19,757.The NSE Nifty is down 172 points at 5,902.HDFC Bank has tumbled 6.7% to Rs 1,666, and Reliance Communications has plunged 5.6% to Rs 734.NTPC and Hindalco have slumped around 5% each to Rs 260 and Rs 188, respectively.Tata Steel and Reliance Energy have shed 4.7% each to Rs 812 and Rs 2,255, respectively.BHEL and Tata Motors have slipped 4% each to Rs 2,318 and Rs 739, respectively.Maruti, ITC and DLF have dropped 3.7% each to Rs 834, Rs 208 and Rs 1,132, respectively.TCS has advanced 1.5% to Rs 952.The market breadth is extremely negative - out of 2,758 stocks traded so far, 2,244 have declined, 477 have advanced and 37 are unchanged.