HOUSTON — Spirit Airlines Inc. said Friday it plans to add 10 new routes from Houston next year, which would nearly double its destinations from Bush Intercontinental Airport.

The low-fare airline said it will begin flying to Baltimore and Tampa, Florida, in March; and to Oakland, California, in April.

Spirit is seeking foreign government approval to begin flights in May to Cancun, Los Cabos and Mexico City; Managua, Nicaragua; San Jose, Costa Rica; San Pedro Sula, Honduras; and San Salvador, El Salvador.

Southwest Airlines Co. is building an international terminal at nearby Hobby Airport to begin overseas flights from Houston next year.