United may soon be feeling heat in Denver

In a move that could not have been viewed as good news in United Airlines world headquarters here, Southwest Airlines late last week said it soon will launch a significant expansion of service at Denver International Airport, where United has long been the dominant carrier.

After recently failing to acquire Frontier Airlines (which has a major hub at DIA), Southwest looks to be moving quickly to add more flights in a bid to alter the market share dynamics at Denver, an increasingly important destination for both business and leisure travelers.

And between March and May of 2010, Southwest hopes to add to that vibrancy by introducing 13 new daily departures and six new destinations to the service it offers from DIA and increase service from Denver to several existing markets.

When all of the new flights are added by May, Southwest will operate 127 daily departures to 43 cities from Denver, up from a mere 13 daily departures in January 2006.