Southwest bids $170 million for Frontier Airlines

Southwest Airlines says it's bidding $170 million to buy Frontier Airlines out of bankruptcy protection. The bid sets up an auction for Frontier. Regional airline operator Republic Airways Holdings Inc. has also bid for Frontier.

Southwest says it will discuss its cash offer with interested parties. It says an auction is expected to begin on Thursday. The auction was originally slated for Tuesday.

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.