A "disorderly" default in Greece could cause more than €1trn (£833bn) damage to the eurozone, a confidential report has warned.
China has cut its annual economic growth target for the first time in eight years, lowering its forecast to below 8% for the first time since 2004.
Recent market uncertainty has seen extreme volatility in investment markets over the last few years.
Eurozone members have delayed the approval of more than half of the €130bn loan for Greece, raising fears the troubled economy will officially default.
Don't listen to the scaremongering - with stocks on the rise and an improved macro outlook, Europe offers rich pickings.
Martin Weale voiced fears over "persistent" inflation yesterday in a hawkish speech underlining the growing splits at the Bank of England over the path of monetary policy.
US GDP for the fourth quarter of 2011 has been revised up from 2.8% to 3%.
Upbeat economic news in the US pushed the Dow Jones through 13,000 on Tuesday, the first time it had been at that level since May 2008.