* Nikkei pares gains after disappointing start to earnings * Fanuc drags down index with loss of 6 pct * Investors cautious ahead of BOJ meeting on Friday By Sophie Knight TOKYO, April 26 (Reuters) - Japan's Nikkei share average ended flat on Thursday after dipping in and out of negative territory as a sluggish start to earnings season and wariness ahead of a Bank of Japan meeting dampened sentiment. The Nikkei ended at 9,561.83, while the broader Topix gained 0.1 percent to 810.10. Positive U.S. corporate earnings and the acquittal of ruling power heavyweight Ichiro Ozawa of violating fundraising laws led to modest gains in the morning, but the market reversed later in the day as underwhelming earnings from the likes of industrial robot maker Fanuc Corp took their toll. Fanuc was the most heavily traded stock on the main board, down 6.1 percent. It was also the top weighted loser and took 36 points off the benchmark. Market players have been holding back from taking major positions this week in anticipation of a Bank of Japan meeting on Friday to decide whether to introduce further easing measures. The Federal Reserve stood pat on its monetary policy on Wednesday and reiterated its expectation that interest rates would not rise until late 2014, while the BOJ is widely predicted to boost asset purchases by up to 10 trillion yen ($123 billion) and some strategists say it may also buy longer-dated Japanese government bonds in an effort to rev up the economy. Hideyuki Ishiguro, assistant manager of investment strategy at Okasan Securities, said the BOJ's expected move had been largely priced into markets, but would have one advantage - demonstrating that the central bank can act independently of its U.S. counterpart. "I think it may change overseas investors' thinking of the BOJ, who believe now that it only acts in response to the U.S.