At least four contractors have been prequalified to bid for the deal to expand the existing passenger terminal building at Dubai’s Al-Maktoum International airport.

Prices are expected to be submitted by 22 September. The original deadline was December 2014.

The contractors known to have been prequalified include the local Al-Jaber Engineering & Contracting and Khansaheb Civil Engineering, South Korea’s Hyundai Engineering & Construction, and the UK’s Laing O’Rourke, although Khansaheb and Laing O’Rourke are thought to have declined to bid for the project.

The project owner, government-owned Dubai Aviation Engineering Projects (DAEP), says there are many other contractors bidding for the project, although it has declined to release any additional names.

The airport’s expansion, estimated by regional projects tracker MEED Projects to have a budget of $100m, is designed to accommodate the requirements of low-cost carrier FlyDubai, which is due to commence operations there in late October.

The passenger terminal structure was built by a joint venture of the local Arabtec Construction and Germany’s Max Boegl. The fit-out was completed by South Korea’s Kumho.

The first passenger flights from the airport began in October 2013, following the start of cargo services in June 2010 and general aviation operations in April 2011.

This project is not part of the planned $32bn expansion of Al-Maktoum International, the largest single project in Dubai. The upgrade will bring the airport’s capacity to 200 million passengers a year upon completion, making it the world’s largest airport.