Southwest Airlines has submitted an improved bid in its competition with Republic Airways Holdings to buy Frontier Airlines out of bankruptcy.

If Southwest’s cash offer of more than $170 million is chosen as the winner in a U.S. Bankruptcy Court auction later this week, it is likely to bring Southwest service to Dayton International Airport, where Frontier currently offers nonstop service to its headquarters city of Denver.

Iftikhar Ahmad, Dayton’s aviation director, has had continuing discussions with Southwest about serving Dayton. The low-fare carrier also serves Columbus and Indianapolis.

Southwest said Monday, Aug. 10, that if it wins the bidding, it will maintain service in all existing markets, as well as add new nonstop routes from Denver that are not served by either Southwest or Frontier today.

“Given Southwest’s history and track record of running a successful airline, we believe that our bid is the best option on the table for Frontier, Southwest and the traveling public,” said Gary Kelly, Southwest’s president, chief executive officer and board chairman.

Last week, Southwest made a $113.6 million offer last week to buy Frontier out of bankruptcy reorganization.

That offer challenged a previous $108.75 million bid by Republic Airways Holdings to buy Frontier. Indianapolis-based Republic Airways, the holding company that owns Chautauqua Airlines, Republic Airlines and Shuttle America, is Frontier’s biggest creditor.

Frontier has been operating under U.S. Bankruptcy Court protection from creditors since April 2008.

Republic Airways has not modified its original bid for Frontier and won’t say whether it is prepared to do so, spokesman Carlo Bertolini wrote in an e-mail response Tuesday to the Dayton Daily News.

Formal bids were due to be filed on Monday with the federal bankruptcy court in New York City that is supervising Frontier’s reorganization. The court is to supervise an auction later this week to determine which bidder could claim Frontier.

Bids could be modified during the court-supervised auction process, according to Bertolini.

Contact this reporter at (937) 225-2242 or jnolan@DaytonDailyNews.com.