Frontier Airlines (F9, Denver International) has announced it will scale back its Denver International hub operations next year as part of its transition into an Ultra Low-Cost Carrier (ULCC). On acquiring the carrier in December last year, Phoenix-based investment firm, Indigo Partners LLC, announced plans to complete Frontier's transition into a ULCC as started under its previous owner, Republic Airlines (Indianapolis International).

Quoting a letter from CEO Dave Siegel to Frontier's Denver employees, ABC News Denver says the carrier will reduce its daily operations from the current 85 daily rotations to 70 with the resulting freed up aircraft to be allocated to other more profitable markets.

Siegel blamed the move on soaring operating costs at the airport brought on by increased taxes and airport charges.

"As an example, Colorado property taxes have doubled in the last two years and airport landing fees are up by 30% over the past three years," the CEO wrote. "The cumulative effect of these increasing costs is that connecting traffic is no longer profitable for our airline."

As a consequence of the decrease in capacity based out of the airport, so the number of employees required would also be affected, Siegel said. Layoffs will be achieved through retirements and natural attrition.