MUMBAI: Equity benchmark sensex tumbled 336.46 points on Thursday following losses in index heavyweights Reliance Industries, Infosys and TCS amid a negative trend in global markets. The 30-share BSE index declined 336.46 points or 0.55 per cent to 60,923.50. Similarly, the NSE Nifty fell 88.50 points or 0.48 per cent to 18,178.10. Asian Paints was the top loser in the sensex pack, tanking around 5 per cent, followed by Reliance Industries, Infosys, Tata Steel, TCS and Dr Reddy’s. On the other hand, Kotak Bank, HDFC, ICICI Bank and NTPC were among the gainers. According to V K Vijayakumar, chief investment strategist at Geojit Financial Services, domestic headwinds like high valuations have become unsustainable and rising commodity inflation will impact the margins of firms. “Sustained selling by institutions — both DIIs and FIIs — indicates that smart money regards the market as overheated and overvalued,” he noted. Elsewhere in Asia, bourses in Hong Kong, Seoul and Tokyo ended in the in the red, while Shanghai was positive. Stock exchanges in Europe were trading on a negative note in mid-session deals. Meanwhile, international oil benchmark Brent crude fell 1.12 per cent to $84.86 per barrel.