The Sensex opened with a positive gap of 70 points at 13,453. The index rallied to high of 13,568, and is now up 135 points at 13,517.ACC, TCS, Tata Motors, ITC and NTPC have rallied over 2% each to Rs 1,040, Rs 1,165, Rs 880, Rs 172 and Rs 137, respectively.Reliance Communications, Larsen & Toubro, BHEL and Bharti Airtel have gained around 1.7% each to Rs 459, Rs 1,440, Rs 2,325 and Rs 614, respectively.Satyam, Infosys, Gujarat Ambuja, Wipro, SBI, Hero Honda, Tata Steel, Bajaj Auto, Cipla, Ranbaxy and Reliance are the other major gainers.