The BSE benchmark Sensex rose by 121 points in early trade today, on continued buying by funds and retailers, amid a mixed trend in Asian markets. The 30-share index, which had gained nearly 844 points in the last five sessions, rose further by 121 points, or 0.68 per cent, to 17,829 in the first few minutes of trade today.The wide-based Nifty of the National Stock Exchange regained 5,400 points level to trade 52 points, or 0.96 per cent, higher at 5,413 points.In Asia, Hong Kong's Hang Seng Index rose by 0.13 per cent, while Japan's Nikkei Index down by 0.43 per cent in early trade today.