Two AZUR trains are now running on the Green Line.
According to STM, the two trains will run at different times of the day, depending on the operational requirements.
The first AZUR train started service on the Green Line in August. The purpose of the first car was to run tests to analyze how the train operates while carrying a normal passenger line.
Similar tests were carried out on the Orange Line in February 2016 but the rollout of the new Metro cars was stopped due to malfunctions.
The STM says it is continuing the process of gradually integrating AZUR trains on the Green Line and there are currently 29 trains waiting to be put into service.