How do credit ratings vary by country and by ratings agencies? The UK has had the outlook on it's Aaa Moody's rating changed to negative in a range of adjustments by the major credit agency including downgrades for Italy, Malta, Portugal, Slovenia, Slovakia and Spain.

Moody's announced the nine rating changes yesterday with France and Austria sharing the same fate as the UK with their outlooks also being changed to negative. A "negative outlook" means there is approximately a one in three chance that Britain will lose its AAA rating with Moody's in the next 18 months.