The Sensex is now up 172 points at 15,432.NTPC has surged nearly 3% to Rs 168. Reliance Energy has soared 2.5% to Rs 800.Larsen & Toubro, ITC, ACC and Ambuja Cements have rallied around 2% each to Rs 2,501, Rs 171 and Rs 1,044, respectively.HDFC Bank, Bajaj Auto and Reliance Communications have advanced 1.7% each to Rs 1,180, Rs 2,332 and Rs 550, respectively.