SkyWest Airlines has ordered seven Embraer 175 regional jets for operation with Delta Air Lines and cancelled commitments for three E175s it had intended to fly for Alaska Airlines.

The Utah-based regional carrier announced the fleet changes on 7 August, the day after Delta disclosed plans to cease partnerships with two regional carriers and shift more flying to three remaining partners.

The remaining partners are Endeavor Air, Republic Airways and SkyWest.

SkyWest will receive the seven new E175s between late 2019 and mid-2020, it says.

The twinjets were already included in Embraer's backlog under an undisclosed customer, the airframer states. The deal has a list-price value of $340 million.

The aircraft will replace seven Bombardier CRJ900s SkyWest had intended to operate for Delta.

Delta holds the orders for those seven CRJs and appears destined to shift them into the fleet of Endeavor Air, which on 6 August announced plans to operate seven new CRJ900s.

Additionally, SkyWest says it has reached an agreement to operate a separate six used E175s for Delta starting in early 2020. Delta will finance acquisition of those aircraft from "a regional partner transitioning out of Delta Connection", SkyWest says.

As part of its regional operation overhaul, Delta is ending agreements with GoJet Airlines and Compass Airlines.

Remaining partners Endeavor, Republic and SkyWest will "focus on specific regions of the US", Delta says.

SkyWest confirms it will be "Delta's primary regional operator in several western US cities by mid-2020, including Los Angeles, Salt Lake City and Seattle".

SkyWest also announced it has cancelled three E175s it intended to operate for Alaska, which operates a major Seattle hub.

"We worked with Alaska to meet their current needs and will continue to do so as those needs continue to evolve," SkyWest says about the move, without elaborating.

Alaska did not respond immediately to questions about the cancellations, which leave SkyWest with no outstanding orders for Alaska-earmarked aircraft.

At the end of June, SkyWest operated 32 E175s for Alaska, while Alaska's corporate sibling Horizon Air flew 28 of the type, recent financial filings show.