The benchmark Sensex gave up some of its early momentum, but was trading up by over 109 points on firm buying in IT, technology and telecom sectors.
Bullish earnings from IT major Infosys and positive macro data amid above normal monsoon projection lifted sentiment.
The Sensex resumed at 25,833.16 before quoting at 25,736.09 at 1206 hours, a gain of 109.34 points, or 0.43 per cent. The NSE 50-share Nifty also climbed 29.25 points, or 0.37 per cent, to 7,879.70 at 1206 hours.
Major gainers were Infosys 6.48 per cent, Cipla 1.73 per cent, Lupin 1.18 per cent, HDFC Bank 0.86 per cent, Asian Paints 0.68 per cent and L&T 0.53 per cent.
Foreign portfolio investors (FPIs) bought shares to the tune of Rs 644.27 crore last Wednesday, as per provisional data.
Overseas, Asian markets dropped after major oil producers failed to reach an agreement to freeze output in Doha over the weekend. US stocks closed modestly lower on last Friday as a retreat in oil prices weighed on energy shares.