The use of so-called emergency liquidity assistance (ELA) by Greek banks rose by 4.3 percent in May from the previous month as deposit outflows continued, Bank of Greece data showed on Tuesday. Emergency funding from the Greek central bank, which is more costly than borrowing from the European Central Bank, rose to 77.58 billion euros ($87.1 billion) last month from 74.37 billion in April, the data showed. Official data show Greek banks suffered deposit outflows of 35.1 billion euros over December to April as jitters over the government's standoff with its euro zone partners on a cash-for-reforms deal prompted savers to withdraw cash.