The Bank of Japan board voted unanimously Wednesday to hold its key interest rate at zero to 0.1 per cent in an expected move aimed at stimulating the economy. Last week, the government said the nation's economy expanded at an annualized pace of 4.1 per cent in the quarter that ended March 31 as increased domestic consumption and public spending supported a recovery. In late April, the bank decided to expand an asset-purchase programme to 70 trillion yen (877 billion dollars) from 65 trillion yen to help prop up the economy amid mounting pressure from lawmakers.