The government will select just one firm from all bidders to run four high-speed train lines, probably by the third quarter of the year, Transport Minister Chadchat Sittipunt said on Wednesday.
The minister said bids will cover trains and their signal systems. Bidding on civil work will follow, he added.
Train manufacturers from China, Japan, Spain, South Korea and France have so far shown interest in building and running high-speed trains. There are high-speed trains in all five countries.
Mr Chadchat said the government will select only one winner to operate the four lines. The government "does not want to have four different systems of the high-speed train on four routes because that could mean high maintenance costs," he said. "So only one firm will be selected."
The first four lines to be put to bids will run from Bangkok to Pattaya, Phitsanulok, Nakhon Ratchasima and Hua Hin.
Once it is running, the eastern train to Pattaya will be extended to Rayong and probably Chanthaburi and Trat. Long range plans call for other extensions as well. The northern train will be further built from Phitsanulok to Chiang Mai; Nong Khai is already planned to be the eventual terminus of the Northeast route from Nakhon Ratchasima, and the line to Hua Hin will go further south to Padang Besar in Songkhla province, at the Malaysia border.
The government expects the country's first high-speed train between Bangkok and Pattaya to be running by 2018. The lines to Phitsanulok, Nakhon Ratchasima and Hua Hin are scheduled to be completed in 2019.
High-speed train plans are central to the government's two-trillion baht scheme for megaprojects to improve infrastructure.