TOKYO, July 7 (Reuters) - Japan's Nikkei share average

fell on Monday as cautious investors weighed the details of U.S.

President Donald Trump's tariffs and their impact on corporate

outlook.

The Nikkei fell 0.46% to 39,628.41 by the midday

break, after opening marginally lower.

The broader Topix fell 0.45% to 2,815.36.

"Investors turned bearish when they saw a small decline in

the Nikkei and sold more stocks," said Shoichi Arisawa, general

manager of the investment research department at IwaiCosmo

Securities.

"The market was awaiting any details of the U.S. tariffs.

Investors wanted to stay away from buying stocks until the

details became clear," he said.

The United States is close to finalizing several trade

agreements in the coming days and will notify other countries of

higher tariff rates by July 9, Trump said on Sunday, with the

higher rates scheduled to take effect on August 1.

Yaskawa Electric ( YASKF ) tanked 8.81% to become the biggest

percentage loser on the Nikkei. The machinery maker on Friday

cut its annual operating profit forecast, citing uncertainties

about the demand outlook due to the effect of U.S. tariff

policy.

Yaskawa said it did not factor in the effect of U.S. tariff

policy when it made the forecast in April.

Yaskawa's peers SMC Corporation and Fanuc ( FANUF )

lost 7.34% and 3.23%, respectively.

Automakers fell, with Toyota Motor ( TM ) and Honda Motor ( HMC )

dropping 1.11% and 1.63%, respectively.

Nissan Motor ( NSANF ) slipped 4.35%, following a local media

report that the automaker is in discussions with Taiwan's

Foxconn about electric vehicle collaboration that

could save its Oppama plant in Japan from closure.

Start-up investor SoftBank Group fell 1.64% to

become the biggest drag for the Nikkei. Chip-equipment maker

Tokyo Electron ( TOELF ) slipped 0.68%.

Staffing agency Recruit Holdings ( RCRRF ) rose 2.26% to

become the biggest support to the Nikkei.