The 30-share index, which had lost over 778 points in the previous five sessions, fell by 21.26 points, or 0.11 per cent, to 18,771.61 in early trade, with stocks of IT, realty and oil and gas sectors leading the fall.
Similarly, the wide-based National Stock Exchange index Nifty shed 3.55 points, or 0.06 per cent, to 5,655.20.
Brokers said besides a weak trend in the Asian region in line with overnight losses on the US markets, continuing worries over the country's political stability dampened the trading sentiment here.
The US Dow Jones Industrial Average ended 0.62 per cent lower in yesterday's trade.