In February 2012, Frontier Airlines cut five nonstop routes from Milwaukee. This move "reduced Frontier's daily departing flights out of Mitchell International from 32 to 18," or 56%. Frontier announced further layoffs in conjunction with this route change: up to 446 Milwaukee-area employees were affected by the job cuts that occurred between April 15 and April 30, 2012.
In October 2013, Republic Airways Holdings entered into an agreement with private equity firm Indigo Partners to sell Frontier Airlines for approximately $145 million. According to Indigo, the transaction would further Frontier's evolution into an ultra-low-cost carrier. In December 2013, Indigo Partners LLC, through an affiliate, completed the purchase of Frontier Airlines from Republic Airways Holdings. The airline's headquarters will remain in Denver. Republic Airways Holdings subsidiary Republic Airlines no longer flies Embraer 190 aircraft on behalf of Frontier, as of January 1, 2014.
After making a codeshare agreement with Lufthansa that went into effect in 2010, jetBlue transitioned to the Sabre reservation system used by Lufthansa, enabling the airlines to sell tickets on each other's flights, transfer luggage and passengers between the two carriers, and combine frequent flyer programs,. By making use of JetBlue's North America routes as a feeder network, the agreement put Lufthansa in a position to operate quasi-hubs in New York–JFK and Boston Logan.