The 30-share index, which had gained 617.71 points in the previous three sessions, fell by 49.33 points, or 0.23 per cent, to 21,277.09 with power, PSU, capital goods, realty, auto and banking sector stocks coming under pressure.
In a similar fashion, the National Stock Exchange index Nifty shed 15.35 points, or 0.24 per cent, to 6,348.55.
Brokers said besides profit-booking by participants after three sessions of gains, a weak trend at Asian bourses led to the decline in the benchmark Sensex.
Among other Asian markets, Japan’s Nikkei was down 0.36 per cent, while Hong Kong’s Hang Seng fell 0.20 per cent in early trade.
The US Dow Jones Industrial Average ended 0.03 per cent up yesterday.