The Bombay Stock Exchange benchmark Sensex today opened higher by over 218 points on widespread buying by funds, as the Asian markets firmed up in tandem with the recovery in the US markets on last Friday. The 30-share index, which had lost nearly 228 points in the previous session, shot up by 1.2 per cent to 18,216 points in the first five minutes of trading. All the sectoral indices were trading in positive zone with gains up to 2.01 per cent.The broad-based National Stock Exchange index Nifty also rose by 1.1 per cent when it gained over 60 points to trade at 5,469points.Meanwhile, Hong Kong's Hang Seng index was up by 0.92 per cent, while the Japanese Nikkei gained 1.61 per cent in the morning trade today. The US Dow Jones Industrial average ended 1.65 per cent higher in the previous session on Friday.