The 30-share barometer, which gained 417.84 points in the previous two sessions, moved down by 23.85 points, or 0.11 per cent, to 21,110.36, with auto, power and realty sector stocks falling the most.
Similarly, the wide-based National Stock Exchange index Nifty, moved down 3.15 points, or 0.05 per cent, to 6,269.60.
Brokers said besides profit-booking by speculators, a weak trend on other Asian bourses, tracking a drop on the US markets after weaker-than-expected jobs data, influenced the sentiment here.
In the Asian region, Japan's Nikkei was trading 2.05 per cent down, while Hong Kong's Hang Seng shed 0.86 per cent in early trade today.
The US Dow Jones Industrial Average ended 1.09 per cent lower in yesterday's trade.
