United and American have each announced new Mexico City routes for next winter.
United will fly daily from Denver to Mexico's capital from Oct. 26 through March 27. The flight will compete with daily year-round service by Aeromexico and Mexican discounter Volaris.
American, meanwhile, will connect Chicago O'Hare with Mexico City from Oct. 26 through March 28. The carrier will join a crowded market, which already includes service by United, Aeromexico, Volaris and Viva Aerobus.
United has also announced a second daily Latin America route from Denver that will commence on Oct. 26. The service, between the Mile High City and Punta Cana, will be the westernmost route to the Dominican Republic, United said.
United will fly Denver-Punta Cana year-round. Service will be daily until mid-August, then switch to Saturdays only until late October.
United first announced the new Denver routes in late April.