Mumbai: The BSE Sensex Wednesday tumbled over 349 points to close at 27,527.22 on weakening global cues after the latest poll suggested that Republican Donald Trump was slightly ahead of market favorite Hillary Clinton in the US Presidential race.
Also, the broader NSE Nifty broke below the 8,600-mark level to close at an over three-month lows.
Investors are also waiting the US Federal Reserve's interest-rate decision later Wednesday.
The 30-share index stayed in the negative terrain for the whole day and settled lower by 349.39 points, or 1.25 per cent -- its biggest single-day fall since October 13 -- at 27,527.22. This is the weakest closing since October 17 when it had closed at 27,529.97. The gauge had lost 64.90 points in the past two sessions.
The broader Nifty also succumbed to selling pressure and slipped below the 8,600-mark to hit a low of 8,504.85 before ending 112.25 points, or 1.30 per cent down at 8,514, its lowest closing since July 21.
ONGC was the top Sensex loser, skidding 4.10 per cent to close at Rs 277.35, followed by Tata Motors, which fell 3.19 per cent to Rs 514.
Others that put pressure included SBI, Sun Pharma, RIL, Bharti Airtel, Dr Reddy's, Cipla, TCS, Hero MotoCorp, Maruti Suzuki, Asian Paint and ICICI Bank, falling by up to 2.75 per cent.
(With agency inputs)