The pool of government bonds rated AAA by the three main rating agencies has shrunk by more than 60% since the financial crisis, according to new analysis.
The Governor of the Bank of England has said the financial crisis is "far from over" as he joined fellow central bank chiefs including Ben Bernanke to discuss economic policy.
The S&P 500 is on the verge of passing its all-time closing high after rising as much as 0.5% in early trading.
The Financial Services Authority has finalised new rules and regulations for financial benchmarks as it attempts to "bring integrity" back to the London Interbank Offered Rate.
Shares in asset management giant Schroders were up sharply in early trading after the group announced it had agreed a deal to buy Cazenove Capital for £424m.
Cyprus has agreed a €10bn bailout deal that will force large losses on some big deposit holders but avoids a controversial levy on all bank accounts.
At first glance, Schroders' confirmation that is in talks to acquire Cazenove Capital makes perfect sense.
Japan's Nikkei index experienced its biggest fall since November as concerns about Cyprus and the eurozone continued to batter markets.
Police have searched International Monetary Fund (IMF) head Christine Lagarde's Paris apartment as part of an investigation into suspected embezzlement, Reuters reports.