The BSE benchmark index Sensex rose by over 106 points in early trade today on sustained buying by funds and retail investors amid a firming trend in Asian markets. The 30-share index, which had gained 135.36 points in the previous session, rose further by 106.58 points, or 0.58 percent, to 18,396.31 points. The wide-based Nifty of the National Stock Exchange moved up by 33.15 points, or 0.60 per cent, to 5,597.45.