The Northern Ireland Executive has given its approval for the Department of Agriculture and Rural Development headquarters to move to Ballykelly.
DARD has said around 700 posts will be relocated to the former Shackleton army barracks in two phases.
A DARD spokesperson said 340 posts should be relocated by the end of 2017 when building work is completed.
The confirmation comes despite the fact that Strabane had topped a table of suitable locations for the Civil Service jobs.
Strabane Cllr Patsy Kelly has said the Agriculture Minister Michelle O Neill has still not explained why Strabane was overlooked for these jobs:
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