Five giant bidders are expected to join the upcoming auction of the 224.54-billion-baht high-speed railway linking Don Mueang, Suvarnabhumi and U-tapao airports, says Industry Minister Uttama Savanayana.
But he declined to disclose the company's names, saying only that the project has been in the cross-hairs of several local and foreign investors.
These are likely to include BSR Joint Venture, a consortium of BTS Group Holdings Plc (75%), Sino-Thai Engineering and Construction Plc (15%) and Ratchaburi Electricity Generating Holding Plc (10%).
PTT Group and Charoen Pokphand Group have also expressed their intention to join the auction and seek investment partners, along with firms from Japan and China.
The high-speed railway linking three airports is part of the government's much-touted Eastern Economic Corridor (EEC) scheme, which will be conducted under a public-private partnership model.
The 2018 EEC Act also allows foreign investors to own up to a 51% stake, compared with the normal investment law capping their share at 49%.
The EEC Office has already unveiled the terms of reference for interested bidders, but it will announce bidder qualifications and conditions from the end of May onward.
Bidding papers will be on offer for three weeks during June and July.
All bidders have roughly four months to prepare their documents, while the EEC Office will team up with other government agencies and the Industry and Transport ministries to handle the auction.
That process will include running two meeting rounds, opening a Q&A session and making a site visit.
The bidders must submit their papers on Nov 12, and the related auction committee plans to announce a winner in late 2018.
Mr Uttama said the high-speed railway will be developed based on the route structure of the Airport Rail Link (ARL).
The ARL spans 29km from Phaya Thai to Suvarnabhumi airport, while a 21km extension route between Don Mueang and Phaya Thai is being developed.
He said a new railway structure between Suvarnabhumi and U-tapao airports will stretch 170km with five stations.
As a result, the winning bidder must not only join the high-speed railway project but also manage the ARL route, which has been beset by a number of problems, including an accumulated loss of 1.79 billion baht, on top of construction debt worth more than 33 billion baht.
The ARL, operated by the State Railway of Thailand (SRT), also has limited trains in service and has thereby suffered from overcrowding.
Mr Uttama said the winning bidder also has to develop two land plots owned by the SRT along the route at Makkasan and Sri Racha, with sizes of 150 and 100 rai, respectively.