Finding Property Managers

Me and my friend are deciding to lease a commercial building to run a business. We've been going online and noticing that most buildings require a lot of agent fee's and we want to avoid this. That said, we've been walking around and noting down a few buildings that are empty and might have some potential for our future business.

My question is, how do we find the property manager/owner or landlord for these empty buildings? Is there a place where all this information is stored and accessible? Don't know if this is important, but we are in Germany.

Any help would be appreciated.

thanks