Germany and China signed an agreement through their central banks on Friday that could turn Frankfurt into a renminbi-trading center, in what comes as China’s latest attempt to internationalize its currency, Reuters reported. The deal will strengthen trade ties between the two countries. Their annual trade flows exceed Chinese trade with France, Britain and Italy combined. Up to now, strict currency controls mean the renminbi was not freely convertible, making transactions in the currency impractical for all but the largest European companies that have the clout to involve China’s central bank in a deal.