Fitch Ratings said in a statement that emerging Europe is the most vulnerable part of the world to the global downturn and it downrated Bulgaria, Hungary and Romania.
The ratings agency also stated that the global financial crisis has put the ratings of South Korea, South Africa, Russia and Mexico in jeopardy.
European Union members Hungary, Romania, Bulgaria and the Baltic states 'may not be able to handle their large foreign debt burdens, which could spark financial crises,' Fitch said.
Emerging markets such as Hungary have been hard hit by the lack of credit available in world markets as banks become more reluctant about lending and investors shy away from riskier investments.
The ratings agency's move comes nearly two weeks after a Standard & Poor's downgrade turned the east European country into the only European Union member state with a non-investment grade credit rating and is the latest sign that the global financial crisis is still spreading across emerging markets.
'The profound shift in the global economic and financial outlook pose significant real economy and policy challenges for emerging markets,' said David Riley, head of Fitch's Global Sovereign Ratings Group.
He explained that policymakers in emerging economies have less room for mistakes than their counterparts in advanced countries, though are in a better position to deal with the current challenges than at any time in the past.
'Nonetheless, the risks of economic and financial stress that could undermine sovereign creditworthiness have risen and that is reflected in the prospective ratings actions taken today,' he added.