Railway construction in Thailand will present China with many opportunities to work with the Southeastern Asian country in the rail sector, an industry insider says.

"There will be huge room for cooperation," said Yang Yong, an official in charge of relations with Southeastern Asian countries at China Railway Corp.

Yang said Chinese companies have already been extensively involved in helping Thailand to modernize its rail system, and new lines are on the way.

Feasibility research for the 680-km Bangkok to Chiang Mai and 450-km Bangkok to Nong Khai lines, which have long been proposed by Thai rail planners, was carried out by Chinese engineers, Yang said.

On Wednesday, the Thai military junta approved the two railway projects linking southern China and Thailand. These are aimed at promoting regional economic growth and integration between China and Southeast Asia.

Under a 2.4 trillion baht ($75 billion) infrastructure plan covering 2015 to 2022, about 741.4 billion baht will be invested in a 737-km route from Nong Khai province in northeastern Thailand to Map Ta Phut in the country's eastern Rayong province.

The plan also covers a 655-km line from Chiang Khong in the northern province of Chiang Rai to Ban Phachi in the central province of Ayutthaya.

Soithip Traisuth, Thailand's permanent secretary for transport, told the Bangkok Post the two routes will operate at a maximum speed of 160 km/h, less than the 200 km/h planned previously.

"This is to allow a possible shift to higher speeds after more investment in the future," Soithip was quoted as saying.

A study will also be carried out to explore ways to bring construction costs of the dual-track rail system down from about 500-600 million baht per km to around 350 to 400 million, Soithip added.

Wang Mengshu, a tunnel and railway expert at the Chinese Academy of Engineering, said the reason for lower speeds on the new lines could be that they are not as long as high-speed lines in China and there will be many stops. The Bangkok Post said the routes are in line with a proposal by China, which wants to link its southern regions to Southeast Asia through Thailand.

Soithip said that infrastructure development projects, including the two rail lines, are intended to improve connections within Thailand's transport network that include gateways to border trade, key cities, seaports, airports and cargo rail transport centers.

Thailand's military junta expects the rail system to play a significant role in increasing trade with neighboring nations.

China is considering building a 3,000-km high-speed line from Yunnan province, which would pass through Laos, Thailand and Malaysia to Singapore.

This would boost China's GDP and that of the related countries by $375 billion, Zhao Xiaogang, former chairman of China South Locomotive and Rolling Stock Co, a leading Chinese industrial manufacturer and exporter, told China Daily last month.

Contact the writers at zhaoyanrong@chinadaily.com.cn and zhaolei@chinadaily.com.cn