BAE Systems has agreed to sell its Prestwick-based aerostructures business to a Canadian firm for £80m.
Airbus planes provide 80% of BAE aerostructures revenue
Spirit Aerosystems is expected to take over the 830 strong workforce in the summer pending regulatory approval.
The move was announced to the Stock Market and the new company immediately announced plans to "expand" and "grow" the busines in an address to employees.
The business supplies planemakers Airbus and Boeing and had sales of £207m and earnings of £7.4m in 2005.
The aerostructures unit produces structural components, chiefly on wings, similar to that in Spirit's business based in Oklahoma.
Jeff Turner, Spirit's chief executive officer, said: "We will grow our business both by winning new work and by expanding our presence around the world.
"Growth is fundamental to our long-term success as a company.
"We welcome all the new employees to the Spirit family and we look forward in sharing in our future successes together."
BAE Systems aerostructures has a history dating back to the early days of large scale airplane production in Scotland in the 1930s.
The business also has a base in Samlesbury, England.
Spirit AeroSystems is owned by the Onex Corporation.