The indices were supported by buying activity in IT, FMCG and metal stocks, while selling in banking and oil and gas stocks capped gains.
Around 10.34 a.m., Sensex was trading at 40,704.21, higher by 110.41 points or 0.27 per cent from the previous close of 40,593.80.
It opened at 40,592.54 and touched an intra-day high of 40,760.60 and a low of 40,468.24.
The Nifty50 on the National Stock Exchange (NSE) was trading at 11,967.60, higher by 36.65 points or 0.31 per cent from its previous close.
The top gainers on the Sensex were Ultratech Cement, Bharti Airtel and HCL Technologies, while the major losers were ICICI Bank, State Bank of India and IndusInd Bank.