(Updates with details and closing prices)

TOKYO, April 9 (Reuters) - Japan's Nikkei share average

slipped on Wednesday, ending nearly 4% lower in a broad

sell-off, as traders gauged concerns over a potential economic

slowdown amid an intensifying trade war between the United

States and China.

The Nikkei share average fell 3.9% to close at

31,714.03, while the broader Topix dropped 3.4% to

2,349.33.

The index saw significant volatility this week, closing 6%

higher on Tuesday after a 7.8% slump on Monday pushed it to a

1-1/2-year low.

The Nikkei extended its losses to 5.3% earlier in the day

after U.S. President Donald Trump's "reciprocal" tariffs on

dozens of countries took effect, including massive 104% duties

on Chinese goods, deepening his global trade war even as he

prepared for negotiations with some nations.

The deepening losses of the Nikkei index were associated

with a surge of U.S. Treasury yields in Asia trade, in a sign

investors are selling even their safest assets amid the rout,

said Shuutarou Yasuda, a market analyst at Tokai Tokyo

Intelligence Laboratory.

"The markets are now in panic, and any big move could

drive a sell-off of risk assets," said Yasuda.

In Japan, technology stocks drove the losses on Nikkei, with

Advantest ( ADTTF ) and Tokyo Electron ( TOELF ) falling 7.8% and

6%, respectively.

Technology investor SoftBank Group fell 7.2%.

The yen's gain against the dollar pressured exporters,

with the Japanese currency rising as high as 144.865

yen to the greenback due to safe-haven bets.

A stronger Japanese currency tends to hurt shares of

exporters, as it decreases the value of overseas profits in yen

terms when firms repatriate them to Japan.

"Investors are uncertain about how much further the

Nikkei could fall. They are trying to find where the bottom is,"

said Hiroyuki Ueno, chief strategist at Sumitomo Mitsui Trust

Asset Management.

Of the more than 1,600 stocks trading on the Tokyo Stock

Exchange's prime market, 89% saw declines, while 9% posted

gains.