Increases in flights and passengers have prompted officials at Denver International Airport (DIA) to amend plans for expanding the airport, the Denver Post reports.

The hub will now add 39 new gates by 2021 – that’s 50 per cent more new gates than originally planned, airport officials acknowledged. “Almost every single airline wants to grow in Denver,” said DIA spokesperson Stacey Stegman.

United Airlines recently announced plans to relaunch flights between London Heathrow and Denver next year, while Norwegian started flights from Gatwick to the Colorado capital in September.

Opened in 1995 with a capacity to accommodate 50 million passengers annually, DIA had 58.3 million travellers pass through its terminals last year. The renovation and expansion project would increase capacity to 80 million passengers per year.

“This expansion is what the airlines have been asking for and adds capacity so planes are not waiting on the runway,” said Denver City Council President Albus Brooks.

“Airports across the nation are investing billions into their infrastructure, but few are adding capacity by expanding gates. This gives Denver a competitive advantage.”

DIA currently has 107 regular gates and 42 “apron load” areas where passengers can board planes from the tarmac.

The gate additions are part of a $3 billion renovation plan that includes terminal and concourse expansions, improved roadways, and laying the groundwork for a seventh runway at the airport.

The project will also include relocating security checkpoints and adding new concessions and other public facilities.