China's military has amended its aviation code for commercial aircraft to allow more flights in the holding spaces above airports.

Major amendments to the airspace restrictions meant the vertical bands between flights would be halved, according to the Air Traffic Control Commission under the Central Military Commission of Communist Party of China (CPC).

The airspace between the altitudes of 8,400 and 12,500 meters, frequently used by civilian flights, used to be divided into seven vertical bands, each 600 meters high. Under the amended code, the number increases to 13, each 300 meters high.

Since only one aircraft could fly in each band, more sections allowed more aircraft to fly at the same time, which would increase the efficiency of air traffic and ease flight delays, it said.

"It is also one of our efforts to come into line with international practice," the commission said in a press release.

Most nations, except Russia, Mongolia, the Democratic People's Republic of Korea and some African countries, had adopted similar restrictions.

The amended code issued by the State Council and the CPC Central Military Commission will take effect on Nov. 22.

According to General Administration of Civil Aviation of China (CAAC), Chinese airlines operated 1,336 scheduled routes -- 1,068 domestic and 268 international routes -- at the end of 2006 and the number is expected to increase.

Chinese airlines are the target of a rising number of complaints about frequent delays, especially in busy terminals like Beijing and Shanghai.