Most of the industrial production means was sold to western capital in the early 90s by the Treuhandanstalt (trust agency), and the companies were closed.
Edit: this was of course one of the biggest waves of privatization Germany has seen. The English Wikipedia has a bit more information: https://en.wikipedia.org/wiki/Treuhand
Buying something to shut it down, might work for internet business which large Internet MegaCorps wish to shut down if they are working on something similar in house.
But a country wide railway line, or a underground cable network and things like that don't just get shut down to suppress competition.
With industrial production means, I meant machines. The machines were sold, and the companies/factories shut down. Not much to produce without machines :)
Edit: this was of course one of the biggest waves of privatization Germany has seen. The English Wikipedia has a bit more information: https://en.wikipedia.org/wiki/Treuhand