The Sensex was trading higher by 35 points, while the Nifty was up 16 points in trade. Among the early gainers in trade apart from Sun Pharma were Carn India, Ultratech Cement and BPCL.
Software stocks exhibited a weak trend with TCS, Infosys and Tech Mahindra among the early losers in trade. Other stocks that lost ground were Dr Reddy's Labs, ICICI Bank and HDFC.
Banking stocks were trading marginally higher in early trade led by gains in Canara Bank, Axis Bank and State Bank of India. However, IndusInd Bank and Bank of Baroda were trading with losses.
Ranbaxy was trading lower following the acquisition of the company by Sun Pharma.
Mid cap stocks were also having a good day in trade with Unitech gaining more than 4 per cent, Power Finance and JSW Energy being among the early gainers.
Real estate stocks saw some heavy buying interest with stocks like HDIL, Godrej Properties and Sobha Developers among the early gainers.
Capital Goods major, Bharat Heavy Electricals continued to fall for the second day in a row on selling pressure. The stock was down more than 2 per cent in trade.
Meanwhile, markets across Asia were trading with losses with the Japanese Nikkei down 1.22 per cent, while the Strait times was down 0.44 per cent.