United Airlines will add service to Frankfurt from its Denver hub next May, making good on plans to expand European links from the Colorado airport.

The Star Alliance carrier will offer year-round daily flights between Denver and Frankfurt with a 219-seat Boeing 787-8 from 2 May 2019, it says today. The flight will complement its seasonal Denver-London service that began this year and resumes in March.

"United is committed to expanding our global network… and we are excited to continue this growth with the addition of new service between Denver and Frankfurt," says Patrick Quayle, vice-president of international network at United.

The Chicago-based airline is in the midst of a growth spurt in Denver. It will grow capacity at the airport 9.7% this year, with the addition of numerous new routes to places like Jacksonville, London Heathrow and Norfolk.

The growth is part of United's larger strategy to boost connectivity at its hubs and recapture what it views as its "natural share" of the US domestic market by growing 4-6% annually through 2020. Capacity will be up 4.5-5% in 2018.

Denver airport is adding gates to handle the growth planned by United and other airlines. Of 39 gates planned for its three concourses, 11 will be added to concourse B specifically for United.

United resumed seasonal Denver-London service this summer after an eight-year hiatus. In August, the airline's president Scott Kirby called the route a "success" in part due to the additional feed from its connectivity growth strategy.

Kirby also said the carrier would "hopefully" add a new European destination from Denver in the near future.

United briefly flew between Denver and Frankfurt in 2001, while fellow Star member and joint venture partner Lufthansa has served the route continuously since that year, the airport says and FlightGlobal schedules data shows. Lufthansa also flies between Denver and Munich.

Frankfurt joins Charleston (South Carolina), Eureka (California), Everett (Washington), Flagstaff (Arizona) and Sonoma County (California) among new routes United will add from Denver in 2019.

The carrier plans to grow capacity by 4-6% next year.

Source: Cirium Dashboard