Hong Kong's Hang Seng index prolonged its upward trend on Wednesday supported by positive US economic data and further declining oil prices. Hang Seng index surged 0.52% or 111.35 points and closed at 21,680.08. Airline sector provided the main upside contribution to the index. China Eastern Airlines Corp gained 1.7%, Air China Ltd added 1.9% and Cathay Pacific Airways Ltd jumped 3.5%. Hang Seng index finished February with a notable monthly gain of 6.3%.