Snapping its four-day long losing streak, the BSE benchmark Sensex today recovered by over 139 points in early trade on emergence of buying by funds, tracking a firming trend in the Asian region. The 30-share index, which had lost 612 points in the previous four sessions, rose by 139.39 points to 19,813.72, with all the sectoral indices, led by metals and realty, trading in the positive zone with gains of up to 1.56 per cent.Similarly, the wide-based National Stock Exchange index Nifty regained psychological 6,000 points mark by rising 43.65 points to 6,010.70.Brokers said emergence of buying by funds after four sessions of losses, driven by a firming trend on the Asian bourses largely in line with late recovery in US stocks inyesterday's trade, helped trading sentiments to improve.Meanwhile, in Asia, Hong Kong's Hang Seng index rose by 0.35 per cent, while Japan's Nikkei recovered by 2.65 per cent in early trade after falling over 7 per cent the previous session. The US Dow Jones Industrial Average ended a shade lower in yesterday's trade.