Japan's Nikkei dips as looming US tariff deadline spurs caution

TOKYO, March 24 (Reuters) - Japan's Nikkei share average declined for a third straight session on Monday as uncertainty ahead of a looming deadline for implementing additional U.S. tariffs sapped investor appetite for riskier assets.

The Nikkei .N225 closed down 0.2% at 37,608.49, while the broader Topix .TOPX shed 0.5% to sit at 2,790.88 after hitting an eight-month peak on Friday.

The Nikkei received some support as a portion of heavyweight shares saw some buying, with AI-focused startup investor SoftBank Group 9984.T climbing 3% to offer the biggest lift.

U.S. President Donald Trump hinted that he would be flexible regarding a new round of tariffs set to go into effect on April 2, helping lift the S&P and Dow at the end of the week. .N

But the benchmark Nikkei index struggled to advance on the day, seesawing between gains and losses as investors took a cautious approach to the impending tariff threat.

Many important details regarding the latest tariffs are still unknown, keeping investors on edge, said Kazuo Kamitani, a strategist at Nomura Securities.

"There's no way to predict it, so we have no choice but to wait for the announcement," Kamitani said.

Major semiconductor-related shares dragged on Monday, tracking their U.S. peers after the Philadelphia SE Semiconductor Index .SOX ended nearly 1% lower on Friday.

Tokyo Electron 8035.T slid 0.8% and Advantest 6857.T declined 1.2%, while Screen Holdings 7735.T tumbled 3.5% to become one of the biggest percentage losers on the Nikkei.

Among other big-name shares, Uniqlo parent firm Fast Retailing 9983.T erased earlier gains to stumble 0.1%, and telecoms company KDDI 9433.T gave up 1.3%. Seven & i Holdings 3382.T rose 1.8%.

Sumitomo Realty & Development 8830.T surged 10.5% after Bloomberg News reported Elliott Management Corp has built a significant stake in the Japanese real estate developer.