The 30-share barometer, which had lost 37.67 points yesterday, fell further by 101.82 points, or 0.38 per cent, to 26,451.10.
Also, the NSE Nifty declined by 37.80 points, or 0.47 per cent, to 8,002.40.
Major losers that dragged down the key indices included Vedanta Ltd, Sun pharma, Bharti Airtel, Axis Bank, Lupin, Tata steel, RIL, ICICI Bank and Dr Reddy.
Investors are cautious awaiting Bihar assembly polls outcome, as also weaker-than-expected Q2 earning by some bluechip companies impacting market sentiments, brokers said.
The Dow Jones Industrial Average, however, ended 0.28 per cent lower in yesterday's trade.