The Sensex tumbled to a low of 10,813 - down 122 points from the high. The index is now down 75 points at 10,830.Dr.Reddy's is up 5.5% at Rs 1,434.HLL and Tata Power have gained 1% each at Rs 254 and Rs 570, respectively.Larsen & Toubro has slumped 3% to Rs 2,394.Hindalco and Reliance Energy have dropped 2.5% each to Rs 158 and Rs 617, respectively.Hero Honda and Maruti have also tumbled over 2% each to Rs 892 and Rs 851, respectively.ACC has dropped nearly 2% to Rs 742.SBI, Ranbaxy, TCS, ICICI Bank, Gujarat Ambuja, ITC, Bharti Tele, NTPC, ICICI Bank and Infosys are the other major losers among the Sensex stocks.