India's key indices S&P BSE Sensex and NSE Nifty50 settled marginally lower on Wednesday in a highly volatile trading session.In the morning session, the indices traded marginally in the red to later rise in afternoon trade, while it tanked towards the end of the session.Accordingly, Sensex closed at 57,892 points, down 0.2 per cent or 105 points, whereas Nifty closed 17,305 points, down 0.1 per cent or 18 points.Banking stocks were the top drags during the session, data showed.Among the stocks, ICICI Bank, Axis Bank, Ultratech Cement, Indusind Bank, and UPL were the top five losers among the Nifty 50 companies, declining 2.2 per cent, 2.0 per cent, 1.9 per cent, 1.4 per cent, and 1.3 per cent, respectively.Tata Consumers, HDFC, ONGC, Reliance Industries, and HDFC Life, on the other hand, were the top gainers in the morning session.