Frontier Airlines on Friday became the latest budget carrier to file for bankruptcy protection, but the airline promised to continue normal operations.

Frontier, based in Denver, said it had filed for protection after its main credit card processor tried to hold back substantial proceeds from its tickets sales. But the airline said it would continue to operate its full schedule of flights and honor ticket reservations.

“To be clear, we filed for very different reasons than those of other recent carriers, and our customers and employees can be confident that we intend to keep on flying and providing outstanding service and products,” Sean Menke, Frontier president and chief executive officer, said in a statement. He said the airline promised to continue “normal operations throughout our reorganization process.”

On Wednesday, Oasis Hong Kong Airlines, a long-haul budget carrier that tried to offer premium service and spacious seats at low prices, suddenly went into liquidation and canceled all flights. At that time, it was the fourth budget carrier worldwide to halt operations over a period of a week and a half. The series of bankruptcies could undermine travelers’ confidence in budget airlines.