The BSE Sensex on Tuesday plummeted 642 points as investors weighed India's fiscal worries because of soaring crude prices in the wake of growing geopolitical tensions in the Middle East.

After nosediving 704 points, the 30-share index ended 642.22 points, or 1.73 per cent, lower at 36,481.09. The broader NSE Nifty too settled 185.90 points, or 1.69 per cent, down at 10,817.60.

On the Sensex chart, losses were mainly driven by Hero MotoCorp, Tata Motors, Axis Bank, Tata Steel, Maruti and SBI - falling as much as 6.19 per cent.

Of the 30 scrips of the BSE gauge, Hindustan Unilever, Asian Paints and Infosys were the three gainers.

Investors were spooked by geopolitical uncertainties over the Saudi oil turmoil amid reports that higher oil prices were likely to severely hit economic conditions in India, which imports more than 70 per cent of its oil needs, experts said.

The attack on the world's largest oil processing facility in Saudi Arabia has led to a record surge in global crude prices.

After soaring as much as 20 per cent to $71.95 per barrel on Monday, Brent crude futures corrected slightly to trade at $67.97 per barrel on Tuesday.

The higher import cost of oil could sharply worsen the current account position, compress profit margins and raise inflation, a Nomura report said.

Tracking the movement in oil prices, the rupee further depreciated by 37 paise (intra-day) to trade at 71.97 per US dollar.

Market participants were also on edge awaiting cues from the upcoming trade talks between China and the US as well as a much-anticipated policy meeting of the Federal Reserve, scheduled to begin later today.

Elsewhere in Asia, the Shanghai Composite Index and Hang Seng ended significantly lower, while Nikkei and Kospi settled in the green.

Stock exchanges in Europe were trading on a mixed note in their respective early sessions.