Atlanta-based Delta Air Lines will move 31 Bombardier CRJs from ExpressJet Airlines to Endeavor Air, ending its contract with SkyWest Inc. subsidiary ExpressJet and expanding flying for its wholly owned regional subsidiary Endeavor.

The 31 Delta-financed aircraft formerly operated by Atlanta-based ExpressJet, comprising 28 CRJ900s and three CRJ700s, will remain based in Atlanta, where Minneapolis-based Endeavor will open a CRJ900 crew base.

ExpressJet said in a statement that it had “mutually agreed” with Delta to wind down the capacity purchase agreement under which ExpressJet flew 28 76-seat CRJ900s and 33 70-seat CRJ700s under the Delta Connection brand. “The agreement … was previously scheduled to expire beginning in 2019,” ExpressJet noted. “The 31 aircraft financed by Delta, including all CRJ900s, will be returned to Delta beginning in fourth quarter 2017.” The remaining 30 CRJ700s not financed by Delta will be transitioned to other ExpressJet major airline partners throughout 2018.

While it is winding down flying for Delta, ExpressJet has enhanced its contracts with Chicago-based United Airlines and Dallas/Fort Worth-based American Airlines. ExpressJet said it has secured a new, five-year extension of its United ERJ145 contract, effective Jan. 1, 2018. Additionally, ExpressJet has reached agreement with American to add eight more CRJ700s to its flying under the American Eagle brand during the 2018 second quarter.

Endeavor, meanwhile, will increase its fleet to 154 aircraft by July 2018. It is adding the 31 former ExpressJet-operated CRJs while reducing its 50-seat CRJ200 fleet from 58 to 42 aircraft. The total net gain in aircraft will be 15, with a decided reduction in 50-seat aircraft.

“The shift away from 50-seat flying allows Endeavor to focus on its dual-class operation, while delivering a seamless customer service experience for customers connecting in some of Delta’s most heavily traversed hubs,” Endeavor said in a statement.

Endeavor announced that it will close its Minneapolis CRJ200 crew base. It will continue to operate a CRJ900 crew base in Minneapolis.

Aaron Karp