After opening on a positive note, the 30-share index turned negative to trade 130.18 points or 0.22 per cent lower at 59,937.44 in initial deals. Similarly, the Nifty fell 25.80 points or 0.14 per cent to 17,891.
After a positive opening, Indian benchmark equity indices slipped into the red on Monday, mainly led by losses in pharma and private sector banks.
At 10: 52 am, Sensex was at 59,988.43, down 79.19 points or 0.13%, while Nifty declined 16.00 points or 0.09% to 17,900.80.
IndusInd Bank, diving over 10%, was the top Sensex loser followed by Asian Paints, Sun Pharma, M&M, Reliance Industries and HDFC Bank.
UltraTech Cement, Titan, Bajaj Finserv, Bharti Airtel, Tech Mahindra and Kotak Bank were among the gainers.
Foreign institutional investors (FIIs) were net sellers in the capital market, as they offloaded shares worth Rs 328.11 crore on Thursday, as per exchange data.
The BSE and NSE were closed on Friday (November 5) for ‘Diwali Balipratipada’.
Elsewhere in Asia, bourses in Hong Kong, Tokyo and Seoul were trading with losses in mid-session deals, while Shanghai was positive.
Meanwhile, international oil benchmark Brent crude rose 1.04% to $83.59 per barrel.