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

After dropping 340 points in the opening session, the 30-share BSE index was trading 282.08 points or 0.054 per cent lower at 52,286.86 in initial deals, while the broader NSE Nifty dropped 77.75 points or 0.49 per cent to 15,650.15. Axis Bank was the top loser in the Sensex pack, shedding over one per cent, followed by IndusInd Bank, TCS, HDFC, ICICI Bank, Reliance Industries and Bajaj Auto.