The trains were ordered as part of a $US 451.9m contract awarded to a consortium of CAF and Thales in November 2013 for rolling stock and CBTC for the new lines 3 and 6. As part of the contract CAF will maintain the fleet for 20 years in a deal worth $US 19.1m.

CAF will deliver 115 cars for the 22.1km Line 3 and 70 cars for Line 6, which will be 15.3km long.