By George Georgiopoulos and Lefteris Papadimas ATHENS (Reuters) - More than a third of automated teller machines across Greece ran out of cash on Saturday before they were replenished as Greeks pulled out money on fears their country was set to crash out of the euro, three banking sources said. Anxious Greeks lined up outside ATMs after Prime Minister Alexis Tsipras made a surprise call for a referendum on austerity terms demanded by lenders, throwing talks with lenders in disarray and putting Greece on the verge of a default. About 35 percent of the ATM network - some 2,000 out of the 5,500 ATMs across Greece - ran out of euro banknotes at one point during the day and were being replenished, the bankers said.