Swiss banking giant UBS says it will post a full-year loss of 2 point 75 billion euros for 2007 due to its exposure to the US subprime crisis. Subprime losses amount to around 8 billion euros, with most of that loss coming in the last quarter of 2007. The news comes as the leaders of Europe's four biggest economies called for greater transparency in credit rating agencies and banks in the light of recent economic turmoil. Speaking after talks in London, the leaders of France, Germany, Britain and Italy said Europe's economy was sound but that an early warning system was needed to deal with global risks. Meanwhile the International Monetary Fund has forecast the global economy is set to post its weakest performance in five years in 2008.