MIAMI — United Airlines is further expanding its presence in San Francisco, after launching today three new routes from its West Coast hub.

Starting on June 8, 2017, the Chicago-based carrier will start a daily Airbus A319 round-trip flight on each route, competing head-to-head against Delta Air Lines, which operates a hub in each of these cities.

According to the Detroit Metropolitan Airport, San Francisco is Detroit’s 13th largest market with more than 350,000 local passengers traveling between the cities each year, and was the largest without at least a second carrier providing nonstop service, according to data from the International Air Transport Association.

“Ensuring our community has excellent access to air service in our top markets has been a priority for our team,” said Airport Authority CEO Thomas Naughton. “The addition of United’s new service to San Francisco is a tribute to the rising strength of our economy, and our team’s hard work and diligence in addressing the growing demand for air service here in our region.”

From Detroit, United currently provides nonstop service to its gateway airports in Denver, New York/Newark, Washington, D.C.-Dulles, Houston and Chicago.

In Cincinnati, United will not only compete against Delta, but also Ultra-Low-Cost Carrier (ULCC) Frontier on the non-stop service to San Francisco.

“United has seen significant growth at Cincinnati over the last three years,” Candace McGraw, chief executive officer, Cincinnati/Northern Kentucky International Airport. “Since 2013, United’s passenger boardings have grown more than 44 percent as a result of expanded schedules and placement of larger aircraft. This new service will offer tremendous convenience and value for travelers, including a great schedule to San Francisco as well as one-stop connections to 30 other destinations.”