In addition to the 20 year maintenance contract, CAF will provide spare parts for two years, while the contract includes an option for the purchase of four more trains for the network's operator, Mettrorey Public Transport.

The 8km Line 3 is currently under construction after the state government awarded a consortium of Garza Parke, Moyeda Construction and Alstom a Peso 2.17bn contract in November 2013. Mexico's Ministry of Communications and Transport (SCT) and the Nuevo León government signed a collaboration agreement for the project, which is budgeted at Pesos 5.6bn, in February 2013.

The line will consist of a 7km elevated section, an 800m tunnel as well as a 200m at-grade section running from Zaragoza to Metropolitan Hospital. The line will have eight stations, and will serve around 280,000 passengers per day, with the state government setting an ambitious opening date of August 2015.

Monterrey's existing metro network consists of the 18.5km east-west Line 1, which opened in 1991, and the 4.5km north-south Line 2, which opened in 1994, and was extended north by 8.5km in 2008.