The tender calls for the design, manufacture and commissioning of up to 133 six-car trains for Line 15 and up to 50 three-car trains for lines 16 and 17. The tender also allows for the purchase of three-car infrastructure monitoring trains.
Each car will be 2.8m wide and 18m long with three sets of passenger doors on each side and full-width gangways between vehicles.
The 1.5kV dc trains will have a maximum speed of 110km/h with two powered vehicles in the three-car trains and four in the six-car sets.
The contract is due to be finalised in the summer.