The Bombay Stock Exchange benchmark Sensex gained nearly 142 points in opening trade today. The 30-share index of the Bombay Stock Exchange, which has lost over 665 points in the previous three sessions, recovered by 141.86 points, or 0.77 per cent, to 18,553.48.Echoing the sentiment, the wide-based National Stock Exchange Nifty index edged up by 43.90 points, or 0.79 per cent, to 5,570.05.