Delta Air Lines is overhauling its Delta Connection regional operation, ending partnerships with GoJet Airlines and Compass Airlines as a means to improve operational efficiency.

The change will leave Delta-owned subsidiary Endeavor Air and regional powerhouses SkyWest Airlines and Republic Airways as Delta's only feeder carriers, the company says.

"In an effort to reduce operational complexity and create better consistency with the overall product and experience for customers, Delta is reducing the number of regional carriers from five to three," Delta says in a 6 August statement.

"This strategic move allows Delta to simplify the Delta Connection network, while maintaining the airline’s network footprint, as the three remaining carriers… will focus on specific regions of the US," Delta adds.

Delta announced the change, first reported by media outlet The Points Guy, in an internal employee memo. The company confirms to FlightGlobal that the changes will be completed in about 11 months.

At the end of June, Compass operated 36 Embraer 175s under Delta's regional umbrella, while GoJet operated 27 aircraft, including 20 CRJ700s and seven CRJ900s, according to Delta's first quarter financial filing.

Delta says its plan calls for "reallocating" those aircraft to its three remaining partners.

How those aircraft will be divvied remains uncertain, though Endeavor announced on 6 August plans to operate 13 Bombardier CRJ700s "previously operated by another Delta Connection carrier."

Neither SkyWest nor Republic responded to requests for more information.

At the end of June, Endeavor operated 156 aircraft for Delta, SkyWest operated 190 aircraft and Republic operated 38 aircraft.

SkyWest has been building up its operation for Delta, announcing in January it ordered nine E175s for placement with the carrier, with deliveries in 2019 and 2020.

The impact of Delta's overhaul on Compass and GoJet, two smaller players in an increasingly-consolidated market, remains unclear.

Neither responded to a request for comment.

Indianapolis-based Compass also operates 20 E175s for American Airlines, while Bridgeton, Missouri-based GoJet operates 17 CRJ700s for United Airlines, according to financial filings and Cirium's Fleets Analyzer.

In June, however, GoJet reached a deal to fly 54 CRJ550s – a 50-seat CRJ700 derivative – for United starting this year.