The Mass Rapid Transit Authority of Thailand (MRTA) has issued a tender for a public-private partnership (PPP) contract to fund, design and construct the western section of the 35.9 km Orange Line. The winning bidder will also be responsible for the mechanical and electrical (M&E) systems for the entire Orange Line, including design, procurement, production, installation, testing, and commissioning.

The M&E equipment will include rolling stock, signalling and train control, power supply, communications, automatic fare collection, platform screen doors, and workshop equipment. Additionally, the company will also be responsible for operating and maintaining the entire line for a period of 30 years. The Government of Thailand will provide a subsidy of THB96 billion to fund the construction of the western section.

Companies bidding for the contract must be at least 35 per cent owned by a Thailand-based entity. Bids must be submitted by July 27, 2022.

The Orange Line will include 27 km of underground section as well as 8.9 section that will be elevated. The 22.57 km eastern section is currently under construction.