Greece had its credit rating cut three levels by Standard & Poor’s, which branded the nation with the world’s lowest debt grade and said a restructuring looks “increasingly likely.”

The move to CCC from B reflects “our view that there is a significantly higher likelihood of one or more defaults,” S&P said in a statement today. “Risks for the implementation of Greece’s EU/IMF borrowing program are rising, given Greece’s increased financing needs and ongoing internal political disagreements surrounding the policy conditions required.”

The downgrade follows Moody’s Investors Service’s decision this month to grade Greece only one level higher and may intensify pressure on European governments to stem the region’s sovereign-debt crisis. Credit-default swaps on Greece, Ireland and Portugal surged to records today on concern governments’ struggles to resolve the turmoil will threaten their ability to pay off their debts.