The Sensex is now down 546 points at 12,526.All index stocks are in negative zone.Maruti has slumped nearly 8% to Rs 756, and Tata Motors has tumbled 7.4% to Rs 674. Bajaj Auto and Hero Honda have dropped around 5.5% each to Rs 2,290 and Rs 647, respectively.SBI has plunged over 6% to Rs 931. Wipro and Larsen & Toubro have shed around 6% each to Rs 523 and Rs 1,523, respectively.HLL, ICICI Bank and ONGC are down around 5% each to Rs 195, Rs 810 and Rs 835, respectively.Out of 2,439 stocks traded so far, 1,687 have declined, 692 have advanced and 60 are unchanged.