The Sensex opened with a positive gap of 296 points at 17,910. The index is now up 635 points at 18,249.Bharti Airtel has zoomed 7% to Rs 992. Reliance Energy and Larsen & Toubro have soared 6.4% each to Rs 1,458 and Rs 3,295, respectively.BHEL has surged 6% to Rs 2,179. NTPC has rallied over 5% to Rs 210.Reliance has gained over 4% at Rs 2,514. Reliance Communications, Hindalco, ONGC and Satyam have moved up 3.5% each to Rs 745, Rs 184, Rs 1,135 and Rs 464, respectively.Grasim, HDFC Bank, Tata Steel and Tata Motors have advanced 3% each to Rs 3,620, Rs 1,413, Rs 862 and Rs 795, respectively.SBI, ACC, Hindustan Unilever and ITC are up 2.7% each at Rs 1,759, Rs 1,046, Rs 212 and Rs 182, respectively.