Boeing is set to take over the non-Airbus portion of Spirit AeroSystems' operations in Belfast, Northern Ireland, after attempts to find a buyer for the site fell through, a Spirit spokesperson said on Tuesday.

In April, European planemaker Airbus finalized a deal to acquire several Spirit AeroSystems facilities tied to its aircraft programs.

Under the terms of the agreement Spirit reached with Airbus, the engineering programs for the A220 wing and A350 engineering program are expected to transfer to the European planemaker, Spirit Aero spokesperson Joe Buccino told Reuters.

"If a suitable third-party buyer is not secured for the remainder of the Belfast site, the A220 mid-fuselage program transfers to Airbus, with the remaining Belfast operations transferring to Boeing."

Last year, Boeing agreed to buy back Spirit in a $4.7 billion all-stock deal, aiming to streamline its operations and improving quality control, years after spinning off the key supplier.

With no buyer secured for the remaining Belfast operations, the facility is now expected to be transferred to Boeing, Buccino said.

A Boeing spokesperson told Reuters that the company "remains committed to its acquisition of Spirit AeroSystems" and that "taking ownership of Belfast is an outcome we've known was a possibility for some time."

The site also produces aerostructures components for Bombardier business jets. The Canadian planemaker is "very actively engaged with all parties to ensure continuity and quality," company spokesperson Mark Masluch told Reuters.

"We remain open to all solutions regarding the site's future," Masluch added, not fully ruling out a potential acquisition.

The news was first reported by the Financial Times earlier in the day.