The 30-share barometer, which lost over 260 points in the previous two sessions, fell further by 89.96 points to 18,088.37 points today, dragged down by profit-booking in IT and capital goods sectors in the first few minutes of trade.
In a similar fashion, the wide-based National Stock Exchange index Nifty fell by 27.25 points to 5,410.10 points.
Brokers said the trading sentiment remained bearish on the back of a weakening global trend as surging oil prices amid a spiralling crisis in Libya raised concerns of a rise in inflation and interest rates.
They said selling was also seen as funds squared up their pending positions on the last day of current month contract expiry in the derivatives segment.
Meanwhile, in other Asian markets, Hong Kong`s Hang Seng index was down by 0.22 per cent and Japan`s Nikkei by 0.43 per cent in early trade this morning.