Credit Agricole, which has poured some 6 billion euros ($7.54 billion) into Emporiki since buying the bank in 2006, could face some 5 billion euros of writedowns if the bank failed, which could force it to undertake a capital increase.

Earlier on Wednesday the bank said it planned to name Xavier Musca, until recently the top financial adviser to former French President Nicolas Sarkozy, as executive vice president in charge of international retail banking including Emporiki.

That appointment, along with the latest talk about contingency planning, comes just days before a Greek election in which many are expected to vote to ditch the country's international bailout - possibly paving the way for a euro zone exit.

Bankers said on Wednesday that up to 800 million euros were leaving major Greek banks daily as polls indicated that the conservative New Democracy which backs the Greek bailout was running neck-and-neck with the leftist SYRIZA party, which wants to cancel the rescue deal.

Another option under consideration is for Credit Agricole to merge Emporiki into a larger conglomerate of Greek banks in which the French lender's stake would be diluted to about 10 percent, the paper said.

Credit Agricole is also looking at transferring some "good" assets from Emporiki to the French bank, the paper said, without elaborating.

Credit Agricole, which declined to comment on the report, has previously said it was moving shipping sector loans from Emporiki to Credit Agricole's investment bank.

Credit Agricole said in May that it had a team working to prepare for possible outcomes from a Greek exit from the euro zone even if it saw that as a less probable scenario.

One source close to the matter told Reuters that Credit Agricole was still considering various scenarios with respect to Emporiki, adding that if Greece leaves the euro zone "it is likely that there would be bank restructuring and mergers in Greece and Emporiki would be a part of that," the source said.

The source added that Credit Agricole's strategy was to reduce its exposure to Emporiki, shifting the funding burden to the Greek Central Bank - which recently agreed to issue emergency liquidity assistance to the subsidiary - and potentially cutting its equity stake if European recapitalisation funds were made available.

Analysts have said cutting Emporiki loose would at least allow Credit Agricole to cap its liabilities in terms of funding the Greek unit as well as any equity it still has in the bank. A quick retreat from Greece could also prevent fallout from a potential Greek euro zone exit such as a drachma devaluation and further loan writedowns.

In a worst-case scenario, 50 billion euros, or a quarter of Greece's gross domestic product (GDP) may be required to shore up its banking system and some analysts believe that the heavily indebted Greek state could end up owning the banks.