To be clear: I prepared my reply long before any answer was given - the text just took me some time.
Should have rather posted it as a reference entry, but I don't know whether that's still possible.
LandesbetriebeThat's a tricky one, actually. It's especially confusing, because other states just call it "Landesbehörde", but it seems to be the same thing. So agency may work - unless there are other agencies (Behörden) referenced. Then, I think you should clarify.
HoldingsI still don't know where both you and Helen take the holdings from? A) To mean holding company - that's not the case here, as shown in my examples. B) Holdings as in "Stocks, property, and other financial assets in someone’s possession" makes no sense then either. Consider: Wholly-owned state assets held by the state?!?
I guess I'd go with your second suggestion and agree.
By the way: Yes, "wholly-owned" takes a hyphen. I was caught off guard, too, but that's the way Oxford spells it:
http://www.oxforddictionaries.com/definition/english/wholly-... . However, because Oxford says "by another company" (not the case here), I would not use it in that regard.