International credit ratings agency Standard & Poor's on Wednesday upgraded Greece's credit rating to CCC with a stable outlook up from the "selective default" level.

The upgrade was widely expected by local and international financial analysts two months after the same agency had granted the debt-laden economy the negative rating, along other similar firms.

Wednesday's raise came after the completion on April 25 of a successful voluntary write down of the Greek sovereign debt load by a third this spring, as part of efforts to counter the debt crisis that has sent shockwaves beyond Greek borders since 2010.

The agency's experts noted that the debt restructuring that eased the burden by some 100 billion euros (131.47 billion U.S. dollars) eased the pressure on Greece in the short-term, warning though that the risk of a disorderly default that could destabilize the entire eurozone has not disappeared.

Greek analysts and local media welcomed the upgrade, noting though that Standard & Poor's analysts stressed that Greece needs to stick to an austerity and reform program to fix its chronic problems.

The eurozone member country is heading to general elections on May 6, with opinion polls showing that anti-austerity parties have gained ground.