Frontier Airlines this spring will launch new routes from Minneapolis-St. Paul International Airport to Cincinnati and Cleveland.

The Denver-based ultra low cost carrier has expanded and contracted several times at MSP over the years. Frontier changed in 2014 from a traditional airline to one with a base fare and extras — including seat assignments, carry-on luggage and snacks — charged a la carte.

From Minneapolis-St. Paul, the airline will fly to and from Cleveland three times and week and to and from Cincinnati four times a week.

"Customers wanting to travel in these markets have told us they want more low-fare options," Daniel Shurz, a Frontier senior vice president, said in a statement.

MSP has seen a rise in overall low-cost carrier traffic, led by Spirit Airlines and now being taken on by the largest airlines.

The airport's largest carrier by market share, Delta Air Lines, offers a basic economy fare option that resembles the low-cost model. United Airlines said earlier this month that it will test-launch its version of basic economy at MSP this winter because the market is used to this style of travel and is better than some at abiding by the strict rules.

Kristen Leigh Painter • 612-673-4767