Equity benchmark Sensex tumbled over 300 points in early trade on Monday, tracking losses in index majors Reliance Industries, HDFC Bank and ICICI Bank amid a weak trend in global markets.

The 30-share BSE index was trading 305.33 points or 0.61 per cent lower at 49,552.91, and the broader NSE Nifty fell 76 points or 0.52 per cent to 14,668.

PowerGrid was the top loser in the Sensex pack, shedding around 2 per cent, followed by Reliance Industries, ICICI Bank, HDFC Bank and IndusInd Bank.

On the other hand, Sun Pharma, Dr Reddy's, Asian Paints and Infosys were among the gainers.

In the previous session, Sensex ended 641.72 points or 1.30 per cent higher at 49,858.24, and Nifty surged 186.15 points or 1.28 per cent to finish at 14,744.

Foreign institutional investors (FIIs) were net buyers in the capital market on Friday as they bought shares worth Rs 1,418.43 crore, as per exchange data.

V K Vijayakumar, Chief Investment Strategist at Geojit Financial Services, said the market is in an excessively volatile zone. Support comes from sustained FII buying which has crossed Rs 7,000 crore during the last four trading days.

"But, there is a major dampener in the form of fast-rising COVID-19 cases, especially in some economically significant cities. Restricted economic activity in these regions might impact the optimistic growth projections for FY 22," he added.

Elsewhere in Asia, bourses in Shanghai and Seoul were trading on a positive note in mid-session deals, while Hong Kong and Tokyo were in the red.

Meanwhile, the global oil benchmark Brent crude was trading 0.50 per cent lower at USD 64.21 per barrel.