The Sensex at the Bombay Stock Exchange gained 61 points in early trade today on sustained buying by funds and retailers amid a firming trend in Asian region.The 30-share barometer added 61.25 points to 17,810 with stocks of healthcare, IT and banking sectors leading the rise. The index had gained almost 437 points in the previous three sessions.In a similar fashion, the wide-based National Stock Exchange index Nifty moved up by 16.75 points to 5,375.45.In Asian region, Hong Kong's Hang Seng rose by 0.18 per cent, while the Japan's Nikkei by 0.10 per cent in early trade today.