China should open more airspace for domestic carriers to help them compete with the fast-growing high-speed railways and to increase efficiency, Liu Shaoyong, chairman of China Eastern Airlines, said Tuesday.

High-speed railways will cover the most developed and populated areas in China, equivalent to more than 60 percent of the country's civil aviation markets, Liu said.

The National People's Congress deputy added: "Carriers are likely to cancel routes shorter than 500 kilometers in these markets, and passenger volume on routes between 500 and 800 kilometers is expected to decrease 20 to 30 percent."

The country plans to build 42 high-speed rail lines spanning 13,000 kilometers over the next three years, which will make it harder for domestic airlines to attract passengers.

Liu proposed that the government allow more airspace for the nation's carriers and speed up construction of parallel routes among Beijing, Guangzhou and Shanghai to enhance flight efficiency, reduce delays and cut carbon emissions.

About 20 percent of China's sky is open to civil aviation, compared with 80 percent in the United States, Liu said.

"The civil aviation industry attaches greater importance to the country's economy, but insufficient airspace, undeveloped regional air, frail innovative ability and incomplete infrastructure weaken our competitiveness," Liu said.

He proposed the country issue a guideline to develop the industry and speed up mergers among domestic carriers. The government should continue to improve stake structure of state-owned airlines, reduce their debt ratio, he said.