Frontier Airlines is adding daily flights from Atlanta to Los Angeles, Las Vegas, New Orleans, New York LaGuardia, Cincinnati and Minneapolis, as it more than doubles its presence here this spring.

The Denver-based ultra low-cost carrier last month said it was adding flights from Atlanta to Miami, Austin and Indianapolis starting in March, and the six additional routes starting April 30 will bring it to a total of 16 destinations served from Hartsfield-Jackson. Frontier is launching a fare sale for flights on all of those routes with fares starting at $19 to $49 one way from Atlanta, with various restrictions.

Frontier's announcement follows an expansion announced last week by ultra low-cost carrier Spirit Airlines, which is launching flights to nine more cities from Atlanta. Ultra-low cost carriers are expanding in Atlanta following Southwest Airlines' acquisition of AirTran and shrinking of its operation here, leaving less competition against dominant Delta Air Lines. The upheaval is prompting airlines to jockey for travelers in Atlanta.