The US dollar weakened against the yen in New York trading, amid expectations that Japanese authorities may intervene in the currency market again after having just supported the yen on Thursday. The dollar index fell 0.16 percent to 99.802, while the dollar dropped 0.8 percent to 158.225 yen, after tumbling as much as 2.4 percent the previous day. The euro strengthened 0.1 percent to 1.1535 dollars per euro, and the pound rose 0.2 percent after the Bank of England held its policy rate as expected. The Bank of Japan voted to keep its short-term rate at 1 percent, while signaling it could raise rates further as soon as its September meeting. Analysts view intervention as a tool that buys Japanese authorities time until fundamentals become more supportive of a stronger yen, and if the yen weakens again to erase its recent gains, authorities are likely to step in with additional intervention in the coming days.