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.

Europe’s Airbus has reached a deal to acquire manufacturing assets from Spirit AeroSystems as the struggling Kansas-based supplier nears its $4.7 billion reacquisition by Boeing.