Company bond yield spreads in the euro-zone's peripheral countries surged to records versus benchmark government debt as the sovereign crisis infects corporate borrowers.

The extra yield investors demand to hold bonds of companies in countries such as Spain and Italy instead of German government debt widened 56 basis points in the past week to 419, Bank of America Merrill Lynch's Euro Periphery Non-Financial Index. The gap has increased from an eight-month low of 241 basis points, or 2.41 percentage points, on March 20.

"It's overdue," said Geraud Charpin, a fund manager at Bluebay Asset Management Ltd. in London which oversees $42 billion. "If a country is in major trouble it's going to have an impact on corporate borrowing and credit ratings. You can't disassociate the sovereign risk from the corporate risk."