The region, annexed by Russia last year, is enforcing a law that rates Sevastopol Marine Plant as of "strategic importance" for the local economy.
It aims to ensure its "uninterrupted operations" and "establish social justice."
The yard will become a state-owned business on Monday.
Crimea plans to modernise the plant.
In the Soviet era, it was one of the world"s leading crane-vessel makers, but by 2010 it had practically stopped operations.
