The BSE benchmark Sensex which opened by almost 112 points in green, lost much of its ground and was trading at 18,672, just 18 points in the positive territory when reports last came in. The 30-share index, which gained 146.83 points in Tuesday's trade, moved up by 111.73 points, or 0.59 per cent, to 18,765.60 in morning deals. In a similar fashion, the wide-based National Stock Exchange Nifty index was trading 4 points in green at 5,618.