Heavy selling was witnessed in metal and power stocks.
Around 10.10 a.m., Sensex was trading at 52,645.30, lower by 127.75 points or 0.24 per cent from its previous close of 52,773.05.
It opened at 52,782.21 and has so far touched an intra-day high of 52,816.31 and a low of 52,607.61 points.
The Nifty50 on the National Stock Exchange was trading at 15,820.25, lower by 49.00 points or 0.31 per cent from its previous close.
Manish Hathiramani, technical analyst with Deen Dayal Investments said: "The index seems to be taking a breather this morning. It has resisted at the 15,900 level yesterday but still seems poised to achieve 16,000-16,100."
"The current support is at 15,700 and as long as that holds on a closing basis, traders can be rest assured that the trend continues to remain on the upside and any bout of selling or correction can be well utilised to accumulate long positions on the Nifty."