Germany's highest civil court ruled on Tuesday that Deutsche Bank failed to properly advise a client of the risks of interest-rate swaps in a verdict that could trigger a slew of judgements against the bank and lead to greater restrictions in the sale of derivatives in Germany.

In its ruling, Germany's Federal Court of Justice ordered Deutsche Bank to repay €541,000 ($769,356) to a small German bathroom-supplies company that bought the swap in the hopes of saving on interest-rate payments.