Aeromexico and Delta Air Lines have applied for five new US-Mexico route authorities from the US Department of Transportation (DOT), adding to their rapidly growing cross border network.

The carriers are seeking authorisation to begin flights between Leon/Guanajuato and both Sacramento and San Francisco, between Monterrey and Los Angeles, and between Morelia and both Chicago and Fresno, according to a regulatory filing on 27 September.

Aeromexico would operate the flights with the Delta code on an up to daily basis with Boeing 737 aircraft.

The Mexican carrier operates 28 737-700s and 19 737-800s, Flightglobal’s Ascend Online database shows.

No airlines fly the Leon/Guanajuato to Sacramento or San Francisco, Monterrey to Los Angeles or Morelia to Fresno routes, according to Innovata schedules. Volaris flies between Morelia and Chicago Midway airport.

Separately, the DOT approved Aeromexico and Delta’s request for authority to fly between Chicago and Cancun on 25 September.