ATHENS/LONDON (Reuters) - At least three companies in Greece including its biggest electronic appliances chain have paid staff in cash, after the country imposed limits on withdrawals from banks last week in an bid to ward off a possible collapse of its banking system. The moves by Greece's Kotsovolos, a unit of Britain's Dixons Carphone , and another two companies are signs of the domestic impact of the financial crisis, after Greece closed its banks and limited withdrawals from automated teller machines (ATMs) to 60 euros (42 pounds) a day. Capital controls have started taking a toll on Greek households' budgets and choking off the normal flow of operations for many businesses. Four banking sources said on Monday Greek banks will stay closed at least until Friday.