Already the largest carrier at Denver International, United Airlines (UA, Chicago O'Hare) has staked its claim to 24 gates out the 39 currently being built by the airport, which is in the midst of a USD1.5 billion construction project.

Due to open by 2021, United is asking Denver City Council to approve an amendment to its lease that would grant it rights to 24 more gates - more than 60% of the additional gates - at the airport, according to the Denver Post newspaper. The amendment is to be considered by the council on January 8.

The Star Alliance carrier currently operates 66 gates at Denver and handles 44% of traffic, ahead of low-cost carrier rivals Southwest Airlines (WN, Dallas Love Field) and Frontier Airlines (F9, Denver International). The former said in 2019 that it would like to add 16 new gates at Denver, while Frontier is also seeking the extra gates from the in-demand capacity.

"We are currently in active use and lease negotiations with other airlines but cannot confirm yet when these will be finalised,” said an airport spokeswoman.

“The expansion is really driven from the fact that over the last several years United has embraced a midcontinent growth strategy,” said Steve Jaquith, a Vice President at United who runs its Denver hub. “Denver is the fastest-growing hub in our network and most successful hub in our network. Geographically, we are very well positioned.” Should the airline gain the extra 24 gates it has requested, United's daily departures from Denver will jump from 500 to around 700 by 2025.

According to the ch-aviation schedules module, United currently controls 46% - around 320,000 weekly seats - in Denver. This is more than second-placed Southwest - 28% and 190,000 seats - and Frontier in third spot - 10% and 70,000 weekly seats - combined. The Coloradan city is only the fourth-largest airport in its network, behind Chicago O'Hare, Houston Intercontinental, and New York Newark. However, this prospective growth at Denver could see the airport move up the rankings.