The Sensex has slipped into negative zone and is now down 55 points at 20,757.Bharti Airtel and HDFC Bank have surged 2.7% each to Rs 962 and Rs 1,701, respectively.Satyam and Mahindra & Mahindra have soared 2.5% each to Rs 424 and Rs 831, respectively. SBI has advanced 2.2% to Rs 2,456.Infosys has gained 1.5% at Rs 1,662, and TCS has added 1.3% to Rs 989.Larsen & Toubro and Reliance Communications are up 1% each at Rs 4,323 and Rs 798, respectively.Hindalco has slumped 4.7% to Rs 207. Tata Steel has plunged 4% to Rs 889.Grasim has shed 3.5% at Rs 3,390. ICICI Bank has slipped 2.7% to Rs 1,327, and NTPC has dropped 2.5% to Rs 262.Reliance Energy and ACC have declined around 2% each to Rs 2,526 and Rs 982, respectively.Cipla has shed 1.7% at Rs 208. Maruti and Tata Motors are down around 1.5% each at Rs 949 and Rs 776, respectively.Out of 2,910 stocks traded so far, 2,395 have advanced, 500 have declined and 15 are unchanged.