Fitch Ratings, an international credit rating agency, Tuesday upgraded Greece's long-term foreign and local currency IDRs to 'B-' from 'CCC', with a credit outlook at "Stable".

The London-based agency said that several reasons contribute to Greece's one-notch upgrade: The Greek economy is rebalancing and the Economic Adjustment Programme (EAP) is on track amid a semblance of political and social stability.

In addition, the most ambitious instance of fiscal consolidation among advanced economies in recent times, structural reforms are progressing, extensive private and public sovereign debt restructuring has put program funding on a more secure footing and the degree of default risk for private creditors has subsided.

"Greece's sovereign ratings are underpinned by its still high income per capita, which far exceeds 'B' and 'BB' medians, its superior measures of governance on most counts and membership of the eurozone, which shields it from balance of payments and exchange rate risks and has facilitated access to unprecedented financial assistance," Fitch said.

The Stable Outlook reflects the assessment that upside and downside risks to the rating are more broadly balanced than in the recent past, added the rating agency.