The deal is worth $580 million.
Boeing said on July 7 it would acquire the business and operations conducted by Vought Aircraft Industries at its South Carolina facility.
Vought, also a U.S. company, builds a key structure for Boeing's 787 Dreamliner airplane.
The $580 million deal is expected to be completed in the third quarter of this year.
"Integrating this facility and its talented employees into Boeing will strengthen the 787 program by enabling us to accelerate productivity and efficiency improvements as we move toward production ramp-up," said Scott Carson, chief executive of Boeing Commercial Airplanes.
Elmer Doty, chief executive of Vought Aircraft Industries, said "the financial demands" of the program were "clearly growing beyond what a company our size can support."
After the transaction, Vought will continue its work on many Boeing programs.
Copyright Agence France-Presse, 2009