Frontier Airlines II (Not to be confused with the first Frontier Airlines which operated from 1950 to 1986) is a subsidiary and operating brand of Republic Airways Holdings. It provides regional service to the surrounding Rocky Mountain States through a code-share agreement with Great Lakes Airlines. Due to financial problems, Frontier Airlines II declared bankruptcy. At the bankruptcy auction on August 13, 2009, Republic Airways Holidings acquired Frontier Airlines and its regional airline, Lynx Aviation as wholly owned subsidiaries. In the spring of 2010 it was announced that the Frontier and Midwest Airlines (another subsiduary of Republic Holdings) brands would merge. In October 2013, Republic Airways Holdings entered into an agreement with private equity firm Indigo Partners to sell Frontier Airlines. In December 2013, Indigo Partners LLC, through an affiliate, completed the purchase of the Frontier Airlines from Republic Airways Holdings.