American Airlines will begin daily nonstop service between Ontario International Airport (ONT) and Chicago O’Hare International Airport (ORD) on Dec. 17.

The new roundtrip service will depart Ontario at 6 a.m. Pacific time and arrive in Chicago at 12:15 p.m. Central time. The return flight will leave Chicago at 6:15 p.m. Central time and arrive in Ontario at 8:48 p.m. Pacific time.

American will operate the route with a 172-seat Boeing 737 configured with 16 first-class seats, 24 Main Cabin Extra seats and 132 Main Cabin seats. The new service will complement existing nonstop flights between Ontario and Chicago operated by United Airlines.

“American Airlines is a long-valued partner of our airport, having served the area’s residential and business communities since 1970,” said Alan D. Wapner, president of the Ontario International Airport Authority and City of Ontario mayor pro tem. “We welcome this new service and wish our friends much success as they continue to invest in our airport and our region.”

American also operates nonstop service from Ontario to Dallas Fort Worth International Airport, Charlotte Douglas International Airport and Phoenix Sky Harbor International Airport, providing connections through several of the carrier’s major hubs.

The announcement comes as Ontario marks the 10th anniversary of its return to local ownership. Since 2016, American has increased its number of flights at ONT by 25% and expanded available seat capacity by 66%.

Flights are scheduled to become available for booking July 6.