Mumbai: Ignoring a weak trend on Asian bourses, the Bombay Stock Exchange benchmark Sensex rose by almost 118 points in opening trade today on selective buying by funds and retail investors. The 30-share BSE index, which lost 188.48 points in yesterday's session, recovered by 117.90 points, or 0.70 percent, to 16,863.25 in the first five minutes of trade today. Likewise, the wide-based National Stock Exchange Nifty Index was also up by 20.10 points, or 0.40 percent, at 5,052.05. All the sectoral indices, led by IT and consumer durables, were trading in the positive zone, with gains of up to 1.25 percent. According to brokers apart from fresh buying by funds and retail investors, covering up of short positions by speculators helped the Sensex to trade in positive terrain, but a weak trend on the other Asian bourses amid worries over the European debt crisis after a major ratings agency downgraded Italy's sovereign debt rating capped the gains. In the Asian region, Hong Kong's Hang Seng Index was down by 0.10 percent, while Japan's Nikkei Index shed 1.41 percent in morning trade today. The US Dow Jones Industrial Average closed 0.94 percent lower yesterday.