Europe’s Airbus has finalized an agreement to take some assets from Spirit AeroSystems, both companies said Monday, completing a critical part of a transatlantic carve-up of the struggling supplier with US rival Boeing.

European plane-maker Airbus will take over parts of Spirit AeroSystems as it and Boeing carve up the key supplier in an effort to improve production quality.

Airbus finalised an agreement on Monday to take over some plants from Spirit AeroSystems in a carve-up of the struggling supplier with rival Boeing , as unions voiced fears over thousands of jobs in Northern Ireland and Scotland.