ExpressJet has long been the largest Delta Connection carrier flying out of Atlanta, and operates about 4.8 percent of the flights out of Hartsfield-Jackson International Airport. It operates 28 CRJ-900s and 33 CRJ-700s for Delta.

But ExpressJet has struggled with delays and cancellations for years, while Delta has made efforts to push its regional carrier partners to improve their operational performance and keep costs down.

ExpressJet ranked 9th out of 12 carriers for on-time arrivals in the first six months of 2017, for example, just ahead of Spirit. Delta ranked 2nd.

The contract between ExpressJet and Delta had been due to expire in 2019, but ExpressJet in October will begin to return the aircraft Delta owns, including all of the CRJ-900s.

Delta plans to keep most of those 76-seat CRJ-900s based in Atlanta and transfer them to Endeavor Air, a Delta Connection carrier based in Minneapolis that is also a wholly-owned subsidiary of Delta, said Delta spokesman Michael Thomas. Endeavor will expand to routes previously operated by ExpressJet.

According to Thomas, Delta “has made considerable investments in the reliablity and overall customer experience” of Delta Connection, and this move “allows us to more effectively continue that investment.”

Delta has touted Endeavor Air’s operational performance, particularly its low flight cancellation rates.

Through 2018, ExpressJet plans to transfer the rest of its Delta Connection aircraft to the flying it does for other major carriers. It announced Wednesday an agreement with American Airlines to add eight CRJ-700s to its American Eagle flying in the second quarter of 2018.

SkyWest will continue to fly as a Delta Connection carrier, along with Endeavor, Minneapolis-based Compass Airlines, Missouri-based GoJet and Indianapolis-based Republic Airways.

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