French banks and insurance companies are willing to participate in international efforts to save Greece from bankruptcy, dpa cited President Nicolas Sarkozy as saying Friday. "On this aspect, we have no fears," he told reporters in Brussels at the end of a European Union summit. "There is a will to save the euro, ensure the stability of the eurozone that is extremely strong." France carries by far the highest share of Greek debt, and therefore risks losing the most in a credit default. A total of 56.74 billion dollars in Greek loans was held by French banks at the end of 2010, compared to just under 34 billion dollars held in Germany. The Moody's ratings agency warned last week that it was considering downgrading three major French banks - BNP Paribas, Societe Generale and Credit Agricole - because of their exposure to Greek public and private debt. Eurozone finance ministers at the start of the week endorsed a Franco-German deal that private lenders would be asked to contribute "voluntarily" to a second Greek bailout, coming on top of a 110-billion-euro (156-billion-dollar) loan package agreed last year. The European Central Bank had warned that any attempt to force banks into participating would likely be considered as amounting to a Greek default by credit rating agencies. Jean-Claude Juncker, who chairs the Eurogroup panel of eurozone finance ministers, said Friday that it was "too early" to speculate about the "volume of the private sector involvement." "I would like the private sector involvement to be significant," he noted. "But don't ask me what significant could mean." He said he hopes to be able to provide more information on July 3, when eurozone finance ministers are due to hold a special meeting in the wake of a key Greek parliamentary vote on bailout-spurred austerity measures.