The BSE benchmark Sensex declined by over 65 points in opening trade today. The 30-share BSE index, which gained 132.16 points in the previous session, declined by 65.19 points, or 0.41 per cent, to 15,937.32 in opening trade.In a similar fashion, the wide-based National Stock Exchange Nifty index shed 22.45 points, or 0.46 per cent, to 4,778.15.