The top two executives at Swiss banking giant UBS have teamed up to blast the negative interest rate environment brought on by the easy money policies of central banks, an indication that patience is wearing thin in some quarters over these emergency measures.

UBS chairman Axel Weber said in remarks to the bank's annual shareholders meeting on May 10: ""The introduction of negative interest rates - now not only in Switzerland, but also in large parts of Europe and in Japan - is an extraordinary measure and should only be used in extraordinary times."