The Sensex tumbled to a low of 10,196 - down 356 points from the day's high of 10,552. The index is now down 170 points at 10,281.Satyam has slumped 6.5% to Rs 625. ACC has plunged over 5% to Rs 745, and Hindalco has dropped 4.4% to Rs 172.Grasim has shed 3.8% to Rs 1,733, and Tata Steel is down 3.5% at Rs 500.HDFC Bank, Maruti and Ranbaxy have declined over 3% each to Rs 739, Rs 744 and Rs 414, respectively.Larsen & Toubro continued to hold gains and is now up over 3% to Rs 2,263. HDFC has advanced 2% to Rs 1,200, and NTPC is up 1% at Rs 111.Out of 2,412 stocks traded so far, 1,675 have declined, 697 have advanced and 40 are unchanged.