Mumbai: The BSE Sensex crashed about 1,940 points to post its biggest single-day fall in nearly 10 months and the NSE Nifty plunged over 568 points to crack below the psychological 15,000-mark on Friday, tracking global selloffs triggered by a panic in bond markets overseas.

Investors also turned cautious ahead of the third quarter GDP data release, besides keeping an eye on simmering geopolitical tensions between the US and Syria.

At the day's close, the 30-share BSE Sensex settled 1,939.32 points or 3.80 per cent lower at 49,099.99 its worst one-day fall since May 4 last year.

Similarly, the broader NSE Nifty plunged 568.20 points or 3.76 per cent to close the session at 14,529.15 the biggest single-day drop since March 23 last year.

On the Sensex chart, all 30 constituents ended in the red, with eight scrips logging over 5 per cent drop.

Sectorally, banking index suffered the maximum loss with over 4.8 per cent drop. Financial and telecom indices too fell sharply by 4.9 per cent and 3.85 per cent, respectively.

"Equity markets opened gap down following spike in global bond yields and extended its weakness further as the session progressed. Panic in global bond markets led to sharp rise in yields which spooked investors amid fears of interest rate cycle reversal," said Hemang Jani, Head of Equity Strategy, Broking & Distribution, Motilal Oswal.

Vinod Nair, Head of Research at Geojit Financial Services, said, "Domestic markets tumbled in line with global trend triggered by a sharp rise in bond yields. Increasing geopolitical tension between the US and Syria aggravated the selling. Q3 GDP data which is to be released today also added volatility in the Indian market."

Although negative, mid and small caps outperformed their larger indices showing investor confidence, he said, adding the market will gain momentum as the global market is expected to stabilise supported by maintaining accommodative monetary policy and a growing economy.

Elsewhere in Asia, bourses closed with heavy losses due to a rout in global bond markets.

Stock exchanges in Europe were also trading with losses in mid-session deals.

Most global markets traded lower after Wall Street's main indexes tumbled, following a steep rise in benchmark US Treasury yields.

Meanwhile, the global oil benchmark Brent crude was trading 1.16 per cent lower at USD 65.34 per barrel.

On the forex market front, the rupee tumbled 104 paise to close at 73.47 against the US dollar.

Gold Declines Rs 342, Silver Plummets By Rs 2,007

Gold prices on Friday declined by Rs 342 to Rs 45,599 per 10 grams and silver plummeted by Rs 2,007 to Rs 67,419 per kg in the national capital, due to selling in the international market, according to HDFC Securities.

The precious metal had closed at Rs 45,941 per 10 grams on Thursday.

Silver plummeted by Rs 2,007 to Rs 67,419 per kg, compared with the previous close of Rs 69,426 per kg.

HDFC Securities Senior Analyst (Commodities) Tapan Patel said, "Spot prices for 24 karat gold at Delhi fell for the third day by Rs 342, in line with selling in global gold prices despite of sharp rupee depreciation."

In the international market, gold was trading lower at USD 1,760 an ounce, while silver was down at USD 26.78 an ounce.

Rupee Tanks 104 Paise To Close At 73.47 Against USD

The rupee dived 104 paise to settle at 73.47 (provisional) against the US dollar on Friday, following a heavy selloff in domestic equities and strong American currency in the overseas market.

At the interbank forex market, the local unit opened at 72.43 against the greenback, then lost further ground to touch an intra-day low of 73.51.

It finally ended at 73.47 against the American currency, registering a massive fall of 104 paise over its previous close.

On Thursday, the rupee had settled at 72.43 against the American currency.

The dollar index, which gauges the greenback's strength against a basket of six currencies, advanced 0.43 per cent to 90.52.

"US bond yields have surged on worries about inflationary pressures due to unprecedented liquidity infusion in the system and a series of economic data, which is indicating that the economy is on the path to normalcy. This has in-turn led to a rebound in the dollar index and prompted a selloff in risk assets.

"We think that the rupee could see some more depreciation till the 73.50 mark, as the narrowing interest rate differential between India and US could prompt some outflows from the Indian bond and equity market," Sugandha Sachdeva VP-Metals, Energy & Currency Research, Religare Broking, said.

However, it is too early to term this as a weakening bias for the domestic currency, and unless it sustains levels below 73.50 comfortably, the scope for appreciation remains, she added.

Meanwhile, Brent crude futures, the global oil benchmark, fell 0.99 per cent to USD 66.22 per barrel.

On the domestic equity market front, the BSE Sensex ended 1939.32 points or 3.80 per cent lower at 49,099.99, while the broader NSE Nifty slumped 568.20 points or 3.76 per cent to 14,529.15.

Foreign institutional investors were net buyers in the capital market as they purchased shares worth Rs 188.08 crore on Thursday, according to exchange data.

(This Story Is A Compilation of PTI Stories)