Overcapacity hits top airlines

China's three main airline groups saw declining yields on international routes last year, despite rosy annual performance reports amid record-low oil prices.

The aggressive expansion of capacity on overseas markets and rising competition on routes to regions such as Japan, South Korea and Southeast Asia have resulted in sharp decline in their yields.

The airlines kept setting up new international routes in 2015 and they had been laying out their latest aircraft on those routes. All three carriers have witnessed a jump on their available seat miles (ASM) on international routes, which measures a flight's passenger-carrying capacity.