* Non-life insurers underperform on worries about falling premiums

* NTT climbs on share buyback plan

By Ayai Tomisawa

TOKYO, Dec 13 (Reuters) - Japan's Nikkei share average fell on Tuesday in choppy trade, snapping a five-day winning streak as investors waited for a U.S. Federal Reserve's meeting to start later in the day.

The Nikkei dropped 0.1 percent to 19,134.73 in mid-morning trade, after briefly touching positive territory when the dollar rose above 115.20 yen.

The benchmark index had risen for five straight days until Monday, supported by a strong performance on Wall Street and a weaker yen.

The Fed is widely expected to hike interest rates for the first time in 2016 at its two-day meeting, with markets pricing in a nearly 100 percent chance of a quarter percentage point increase to the Fed's target range of 0.25 to 0.50 percent.

"The market has already priced in a rate hike and some are ready to take profits after confirming the result," said Masashi Oda, general manager of strategic investment department at Sumitomo Mitsui Trust Asset Management.

He added that after the Nikkei has risen sharply since the U.S. presidential election last month, the market needs fresh catalysts to rise further.

The insurance sector underperformed, down 1.3 percent, and was the second worst performer on the board after the Nikkei newspaper reported that a reference rate that helps determine premiums for optional auto insurance in Japan could decrease by as much as 10 percent in 2018.

Tokio Marine Holdings dropped 2.1 percent and MS&AD Insurance slipped 0.7 percent.

Exporters were mixed, with Honda Motor Co shedding 0.5 percent, Nissan Motor Co adding 0.2 percent and Panasonic Corp dropping 0.3 percent.

Outperforming the market was Nippon Telegraph & Telephone Corp, surging 3.5 percent, after the company said it would buy back up to 1.62 pct of own shares worth 150 billion yen ($1.30 billion).

The broader Topix was flat at 1,531.34 and the JPX-Nikkei Index 400 was also steady at 13,708.36.

(Reporting by Ayai Tomisawa; Editing by Joseph Radford)