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.

The White House on Monday projected that the U.S. federal government's budget deficit will reach around 1.33 trillion U.S. dollars in the 2012 fiscal year ending September 2012, fresh evidence of the mounting budgetary pressure facing the world's largest economy.

The estimate was equal to 8.5 percent of the nation's gross domestic product (GDP) and was higher than the 1.1 trillion dollars predicted last month by the U.S. Congressional Budget Office (CBO), a non-partisan budgetary and economic research agency for the Congress.

The deterioration of the Greek economy accelerated in the final three months of last year, the latest government figures show.

The estimate showed that, compared with a year earlier, Greek GDP contracted by 7% in the fourth quarter of 2011.

That is an acceleration from the 5% contraction in the third quarter.

The report also shows that the Greek economy shrank 6% last year, an increase on earlier estimates and the fifth year of recession.