MIAMI — It is a done deal: Indigo Partners LLC officially completed their purchase of Frontier Airlines Tuesday. The carrier was purchased from Republic Airways Holdings, which had been looking to divest the airline from its portfolio for over a year. Denver will remain the company’s headquarters, according to the new owners.

The sale was originally announced on October 1, 2013, at a list price of $145 million.

With the sale all wrapped up, Frontier is destined to become the newest ultra-low-cost-carrier in the domestic US landscape. “One key element to Frontier’s future success will be operating as an ultra low cost carrier (ULCC) that offers low fares. This model, coupled with the Frontier touch, will ensure opportunities for the Frontier team, and provide safe and reliable ULCC air service to our communities and beyond as we grow Frontier under this vision,” William Franke, Indigo managing partner said in the company’s announcement.

Indigo and Franke are hardly strangers to the world of low-cost-air travel. The company was previously the owner of well known ULCC Spirit Airlines, with Franke as chairman, until last summer, when Indigo dumped the carrier to position themselves for the Frontier purchase. It also owns a stake in European LCCs Wizz Air Holdings and Volaris Airlines. As we noted in a previous article, the sale “amounts to the Spirit playbook relocating from Florida to Denver, Colorado.”

Republic picked up Frontier (F9) in 2009 while the carrier was in bankruptcy, merging it with its other recent acquisition, Midwest. Republic oversaw a turnaround on F9’s finances, and the beginning steps in turning the airline from a modest low cost carrier into the next ULCC. Despite the improvements, the former owners found that the larger airline did not fit the regional airline vibe Republic is known for. Consequently they began looking to offload F9 over one year ago, eventually settling down with Indigo.

Originally founded in 1994 in response to Continental pulling out of Denver Stapleton, Frontier was one of the first airlines to offer high-quality service at a low-cost-carrier price. The airline was the second airline, after JetBlue, to offer onboard LiveTV.  Easily recognizable with its fleet of animal themed tails, the Frontier started out with a fleet of 737s before it switched to an Airbus fleet in 2005.