By Kaori Kaneko

TOKYO (Reuters) - The Bank of Japan is expected to wait until the middle of next year before adopting further stimulus measures, although Donald Trump's election as U.S. president adds uncertainty to the economic outlook, a Reuters poll found on Friday.

Nearly 90 percent of economists surveyed in the past week said the BOJ's next policy action would be to adopt further easing measures. The remainder said an unwinding of the central bank's ultra-easy monetary policy was likely.

"Sharp spikes in the yen against the dollar are unlikely to happen for a while as the Federal Reserve is seen raising rates as expected. This means the BOJ is expected to stand pat," said Izuru Kato, chief economist at Totan Research.

Fifteen of 25 economists who answered a separate timing question expected the BOJ to wait until the second half of 2017 before expanding its already massive stimulus.

Five said a move at the April meeting was likely, while three nominated the January meeting. One each picked the meetings in December and March.

The majority of economists responded to the survey before the result of the U.S. presidential election.

"But there is a chance that worries over the outlook will grow because the formal announcement of policies under a new administration in the U.S. will come later, so we need to monitor it closely," Kato added.

Trump's key policies are seen likely to include enhanced infrastructure spending, in turn leading to higher inflation, but there are concerns over trade policy and geopolitical alliances.

In the near term, much will depend on the U.S. Federal Reserve, which is expected to proceed with a rate hike in December despite the shock Trump win, a separate Reuters poll showed on Wednesday.

If the Fed hikes next month, it will likely boost the U.S. dollar and dent the Japanese yen which traded around 106.60 per dollar <JPY=EBS> on Friday, close to 3-1/2-month low, after rising as high as 101.19 on Wednesday as Trump's victory became more apparent.

In the poll, 19 economists said the central bank would cut its -0.1 percent interest rate further when it next decides to ease policy, and six predicted it would cut both the interest rate and the 10-year Japanese government bond yield target.

Six economists said the BOJ would increase its purchases of exchange-traded funds/real estate investment trusts and four responded that it would boost its buying of commercial paper and corporate bonds. This question allowed multiple answers.

The consensus from the wider poll found the BOJ will hold the -0.1 percent interest rate it imposes on some excess bank reserves steady and will also maintain its 10-year JGB yield target of around zero percent throughout next year.

The BOJ is seen keeping its annual pace of increase in the amount of outstanding of JGB holdings at about 80 trillion yen, the poll showed, but some analysts say the central bank could lower the amount to around 70-75 trillion yen next year and may even drop a reference to the target amount in its policy statement.

Asked whether the government should announce an extra budget for this fiscal year to March, 19 out of 26 economists said it should not, but some of those said the government was likely to do so. Seven analysts in the poll said the government needed to spend more.

"Many countries including Japan, the U.S., China and in Europe will possibly shift towards fiscal policy from monetary policy as central banks are running out of steps to take," said Nobuyasu Atago, chief economist at Okasan Securities.

(Reporting by Kaori Kaneko; Editing by Eric Meijer)