Maintaining the upward trend today, the Sensex at the Bombay Stock Exchange was trading more than 300 points in the positive territory in afternoon deals.The 30-share index had gained over 320 points in the first few minutes of trade today and since then trading in the green. It was trading 316 points up at 15,491, when reports last came in.In a similar fashion, the wide-based National Stock Exchange Nifty index was trading 92 points up at 4,636.