The BSE benchmark Sensex fell below the psychological 20,000-mark on Wednesday, down about 445 points, biggest decline in six months, on frenzied profit-booking and weak trend in Asian markets.
The NSE's broad-based Nifty also closed below the magic 6,000-mark.
The fall was fuelled by speculations that central banks worldwide might raise borrowing costs to cool down inflation, constricting the availability of cash for equity investment.
While the Bombay Stock Exchange (BSE) benchmark index, Sensex, fell by 444.55 points to 19,865.14, National Stock Exchange (NSE) index, Nifty, fell by 132.90 points to 5,988.70.
After a weak opening, Sensex fell to a month's low as selling pressure gathered momentum influenced by melting Asian stocks, led by China, Hong Kong and Japan.
The regional index for Asian markets fell for the third straight session on Tuesday on speculation that governments will take further steps to cool down inflation, coupled with a decline in raw material prices.
China’s stocks fell, driving the benchmark index to the lowest in a month, on speculation the government might intensify measures to curb accelerating inflation including higher interest rates and price controls.
The MSCI Asian Index fell to its lowest level since November 3 in Tokyo, as the Shanghai Composite Index dropped 3.98%.
Of the 30-BSE index, barring Bharti Airtel, all the 29 stocks fell sharply, while all the sectoral indices closed with losses.
The realty sector index suffered the most by losing 3.55% to 3,325.98 on fears of hike in interest rates, which might impact the new construction and home sale.
The metal sector index was second worst performer and shed 3.11% to 16,577.31 after copper, aluminium, zinc and lead fell sharply in London, amid fears that any measure taken by China, the leading consumer of the base-metals, would reduce demand for the commodity.
The capital goods sector index fell by 2.78% to 15,602.93, consumer durable index by 2.58% to 6,715.22 and auto index by 2.22% to 9,983.56.
As the selling pressure spread over a wide-front, smallcap index fell by 2.92% to 10,566.95 and midcap index by 2.15% to 8,266.42.
Investors refrained from creating fresh positions in view of the public holiday on Wednesday.