Boeing [BA] last Friday said it has acquired GKN Aerospace’s site in St. Louis that supports the company’s production of F/A-18 and F-15 fighter aircraft.

Terms of the deal were not disclosed. GKN Aerospace’s St. Louis site has 550 employees, nearly all of whom were hired by Boeing.

Boeing’s military aircraft business, which includes the F/A-18 and F-15 programs, is based in St. Louis. GKN Aerospace in 2001 acquired the St. Louis site from Boeing. GKN said in 2023 the two companies began talks to return the aerostructures manufacturing facility to Boeing to avoid closure.

“This agreement allows us to not only deliver for our customers, but also gives the highly skilled GKN workforce the opportunity to bring their immense talents to bear in support of the warfighter and the St. Louis defense and aerospace industry,” Steve Parker, senior vice president and chief operating officer of Boeing’s Defense, Space & Security segment, said in a statement.

GKN Aerospace is part of Britain’s Melrose Industries.