The spying involved companies in China, Russia, the United States and elsewhere, said the study conducted by Corporate Trust, a security firm.
The study said nearly half of German companies report they have had company secrets stolen and 20 percent indicated they knew information was being hacked, but they did not know who was doing the spying.
The Local.de reported Monday the spying included some cloak and dagger strategies, including spies from the United States who used "special listening devices."
The study of 600 firms said German companies would lose $5.5 billion in 2012 as a result of industrial spying.
Nearly 60 percent of the trade in industrial secrets is perpetrated by a member of a company's own staff, but about half of the companies said they do not employ any specific strategy when staff members travel abroad.