San Antonio, TX – Southwest bids on Frontier Airlines
The Associated Press

Southwest Airlines is making a firm bid to buy Frontier Airlines out of bankruptcy protection. That sets up a Tuesday auction with regional airline operator Republic Airways Holdings Inc.

Southwest spokesman Chris Mainz confirmed to The Associated Press that the airline put in a firm bid for Frontier on Monday. He says more details will come later.

A bankruptcy judge had already approved the sale of Frontier Airlines Holdings Inc. to Republic for $108.8 million. But the process left the door open for other bidders. On July 30 Southwest put in a nonbinding bid of $113.6 million.

Denver-based Frontier has been operating under Chapter 11 protection since April 2008.

Copyright 2009 The Associated Press.