Southwest Airlines (Dallas) is preparing a bid for Frontier Airlines (2nd) (Denver) in an auction next month for the bankrupt carrier. The bid will be at least $113.6 million. This action trumps and so-far out-bids the proposed price previously set by Republic Airways Holdings and will send the process into a bidding war unless Republic now drops out. Therefore Frontier could be quite different in the future and may become a Boeing customer again or be merged. If successful, Southwest is planning to operate Frontier as a subsidiary until it can be merged. Stay tuned.