The BSE benchmark Sensex fell by 103 points in early trade on Thursday on continued selling by foreign funds and retail investors in the absence of any positive trigger.
The 30-share barometer, which had lost 16.90 points in Wednesday's trade, fell further by 103.02 points, or 0.60%, to 17,198.89 in early trade on Thursday.
All sectoral indices, led by realty and auto, were trading in the negative zone with losses of up to 1.02%.
Similarly, the wide-based National Stock Exchange Nifty index declined by 34.95 points, or 0.67%, to 5,204.20.
Brokers said market sentiment remained weak on fresh selling by funds and retail investors on lack of any encouraging factors.
In addition, overnight losses at the US markets on weak report on private jobs growth and poor economic reports from Europe dampened sentiments, they added.
However, sugar company stocks were in demand following the government's decided to free sugar export.
Shree Renuka sugar gained 5.83% to Rs 32,65, Balrampur Chinni mills was up 4.11% to Rs 55.75 and Dwarkesh Sugar Industries rose by 7.53% to Rs 38.55.
Meanwhile, in the Asia region, Hong Kong's Hang Seng index was trading 0.45% higher, while Japan's financial markets were closed for 'public holiday'.
The US Dow Jones Industrial Average ended 0.08% lower in Wednesday's trade.