David Geen, general counsel at ISDA, said the deal struck for holders of Greek debt to face losses of 50% is not expected to be deemed a "credit event," which would trigger payouts on credit-default swaps. The key is that participation in the deal is voluntary. "As far we can see it's still a voluntary arrangement and therefore we are in the same position as we were with the 21% when that was agreed," Geen said. "The percentage [of losses], as far as the analysis for CDS purposes goes, doesn't change things. Typically a voluntary arrangement won't trigger the CDS."