Olli Rehn, the EU commissioner for economic and monetary affairs, said the EU should repeat bank's stress tests as he sees it a very useful instrument of reinforcing confidence for transparency and sound and solid analysis.

The stress tests conducted annually on the largest 91 banks in the EU were adopted in July and showed that only seven banks failed to pass the test, where the results restored confidence, causing the euro to rebound in July after dropping to four-year low in June.