A company spokesman told Reuters the move would not result in any job losses at the Seattle plant.
Once that work moves out of the development center, other projects start coming through, Doug Alder said by phone.
With the move, Salt Lake City will have more than 100 jobs by 2014, while Utah site, which currently has 522 employees, could grow to 650, he said.
At present, the Developmental Center in Seattle does the development work and initial production on the 787-9 horizontal stabilizer.
Boeing expects the Salt Lake City center to deliver their first stabilizer in the first quarter 2013. The date for the first delivery from Alenia is still being finalized, the company said.
Alenia Aermacchi is a subsidiary of Finmeccanica.
The 787-9 is larger version of the Dreamliner, scheduled to commence service in early 2014 after the 787-8 model. The 787-8 Dreamliner was delayed after the horizontal tails, made by Alenia, suffered quality issues.
The head of Boeing's commercial airplanes unit reaffirmed yesterday that the plane-maker can correct a glitch on the 787 Dreamliner and meet its delivery goals for the plane this year. The light-weight, carbon-composite airplane is already three years behind its development schedule.
The first 787-9 horizontal tail will be delivered out of the Seattle facility in the fourth quarter of current year, Alder said. The first out of Salt Lake will be delivered in the first quarter, next year. Delivery date of the first 787-9 horizontal tail from Alenia has not been finalized yet.
(Reporting by Bijoy Koyitty and Durba Ghosh in Bangalore; Editing by Joyjeet Das and Carol Bishopric)