Transdev, Keolis and Lacroix-Savac are all set to play a role, according to AFP.

A final decision is due to be made on June 28 after a vote by the Board of Directors at Île-de-France Mobilités, the organisation in charge of transport in Paris.

Around 200,000 people are set to be accredited for the Paris 2024 Olympics, including athletes, coaches, officials, journalists and other staff.

Île-de-France Mobilités selected the three candidates at a meeting and proposed them for various roles.

All three companies are headquartered in Paris.

Transdev has been proposed for a €21.7 million (£18.5 million/$23.6 million) contract to transport 100,000 accredited visitors, including 20,000 journalists.

Keolis, meanwhile, has been earmarked to transport athletes, with journeys including to and from the Olympic Village and training and competition venues.

The company is also due to be in charge of transporting wheelchair users and those with reduced mobility, with its deal worth €20.5 million (£17.5 million/$22.3 million).

Lacroix-Savac is expected to win the contract for transporting staff from sports federations and broadcasting. 

Ile-de-France Mobilités will provide buses and coaches for the transportation - both electric and non-electric.