The MJM Group has agreed to buy the former Shackleton Barracks military base in Ballykelly.
The firm, based in Newry, specialises in the fit-out of cruise ships and yachts.
It intends to use the Ballykelly site for a new business fitting out private planes which it said will create an initial 100 jobs.
A spokesperson added MJM has a vision to expand that to more than 1,000 jobs as the 621 acre site is developed.
Shackleton was sold by the Northern Ireland Executive, which inherited the site from the Ministry of Defence.
Another part of the Shackleton site is due to become the new headquarters of the Department for Agriculture and Rural Development.
That project received planning permission earlier this week.