Some of Greece's biggest banks may have to shut and merge with their rivals, it has been claimed.
A European official told the Reuters news agency that Greece's four big banks - National Bank of Greece, Eurobank, Piraeus and Alpha Bank - could be reduced to just two.
European leaders are meeting on Sunday in a bid to strike a financial aid deal with Greece.
Greek Prime Minister Alexis Tsipras has told the EU Parliament that any agreement with their neigbours must acknowledge a demand for signs that the country is exiting its debt crisis.
He said that his nation's public debt must be made sustainable, with reforms that share burdens, create jobs and encourage entrepreneurship.
Tsipras told the EU Parliament that the No vote in Sunday's referendum meant he had a mandate for a socially just and economically sustainable solution to the debt crisis.
The Greeks have voted to reject the austerity terms demanded by eurozone creditors - so, what happens next?
Greeks have voted to reject the terms of an international bailout, putting it on the brink of a eurozone exit.
Greece's controversial Finance Minister Yanis Varoufakis has released a defiant statement of resignation entitled 'Minister no more!'