The 30-share BSE index was trading 173.47 points or 0.43 per cent lower at 40,512.03, and the broader NSE Nifty slipped 47.20 points or 0.40 per cent to 11,883.15.
Tata Steel was the top gainer in the Sensex pack, shedding around 2 per cent, followed by Maruti, ICICI Bank, Bharti Airtel, Bajaj Finance, HDFC twins and TCS.