The 30-share barometer, which gained over 271 points in the previous two sessions, moved down by 21.38 points, or 0.10 per cent, to 20,442.68, led by the weakness in realty, metals, FMCG and oil and gas sector stocks.
Similarly, the wide-based National Stock Exchange index Nifty, moved down by 5.00 points, or 0.08 per cent, to 6,068.30.
Brokers said besides profit-booking by speculators after recent gains, a mixed trend at the Asian markets, influenced the sentiment.
In the Asian region, Nikkei at the Japan stock market, was trading 0.92 per cent higher, while Hong Kong's Hang Seng index shed 0.24 per cent in early trade today.