(Updates with closing prices)

By Kevin Buckland

TOKYO, March 19 (Reuters) - Japan's Nikkei share average

sank in the final minute of trading on Wednesday to close lower

as technology shares weighed, while the Bank of Japan kept

interest rates unchanged as widely expected.

The Nikkei finished the day down 0.25% at 37,751.88.

It had been higher most of the day, including immediately after

the BOJ policy decision, but turned flat in the afternoon before

a sudden drop at the close.

It was the second day in a row that the Nikkei had topped

the psychologically significant 38,000 mark, only to pull back

by the end of trading.

By contrast, the broader Topix, which has a lower

proportion of tech stocks, ended the day 0.45% higher.

Traders were cautious with the U.S. Federal Reserve

scheduled to announce a policy decision later on Wednesday and

Japanese markets closed for a public holiday on Thursday,

meaning investors can't react until Friday.

Both chip-testing equipment maker Advantest ( ADTTF ) and

chip-making machinery manufacturer Disco dropped about

5%, tracking a sell-off in U.S. semiconductor stocks overnight.

At the other end, trading houses extended this week's rally

after Warren Buffett's Berkshire Hathaway ( BRK/A ) raised

holdings. Wholesale was the best performer among the

Tokyo Stock Exchange's 33 industry groupings, climbing 2.34%.

Transport equipment was another strong sector,

rising 1.36% as a weaker yen boosted the value of

overseas sales.

The BOJ held short-term interest rates steady at 0.5% in an

unusually early decision that came during morning trading.

The central bank reiterated that the economy was "recovering

moderately", but said the outlook "remains highly uncertain" due

to risks from global trade policies.

The Fed is also expected to leave policy unchanged, and the

focus will be on the impact of U.S. President Donald Trump's

aggressive and erratic tariff campaign on economic projections.

"Concerns about a worsening of the U.S. economy under

Trump's tariffs is deeply rooted," said Kazuo Kamitani, a

strategist at Nomura Securities.

"It will take a toning down on trade policy for the market's

mood to improve. That's what investors are waiting for."