* Wall Street slumps on possible trade curbs, Trump on Taiwan

* Treasuries react to Fed official comments

* Yen up vs dollar

NEW YORK, July 17 (Reuters) - World stock indexes mostly fell on Wednesday, with Wall Street weighed down by the prospect of U.S. trade curbs, while the yen rose sharply in a move suspected to be the result of another intervention from Japanese officials to buttress the currency from multi-decade lows.

Treasury yields gained as New York Federal Reserve President John Williams acknowledged progress in disinflation but said that he wants to see further improvement before cutting interest rates, making the odds of a July rate cut even less likely.

A reduction by September is still seen as a 98% probability, according to CME Group's FedWatch tool.

The benchmark S&P 500 equity benchmark index lost 50.70 points, or 0.90%, to 5,616.01, while the tech-heavy Nasdaq Composite lost 323.94 points, or 1.72%, to 18,185.40.

Chipmaker stocks slumped on a report that the United States is mulling restricting imports of technology to China, coupled with lukewarm messages from Republican presidential nominee Donald Trump about defending key production hub Taiwan.

Robert Pavlik, senior portfolio manager at Dakota Wealth, said he had taken some profits in tech.

"I'm still optimistic that the market is not as expensive as maybe it's feared, but that's because we're so overbought that some near-term selling pressure is likely to develop," Pavlik added.

MSCI's gauge of global stocks fell 4.16 points, or 0.50%, to 827.13.

Shares of artificial intelligence chipmaker Nvidia, fell nearly 6% in early trading after a rocky Asian session for Taiwan's TSMC, which closed 2.4% lower.

Investors earlier this week had formed a cautiously optimistic view of a second U.S. presidency for Trump, who is running against incumbent Democrat Joe Biden.

"Many strategists have suggested (Trump) is bullish for equities, and I'm just not sure about that," said Benjamin Melman, global chief investment officer at Edmond de Rothschild Asset Management.

YEN JUMPS

The yen has posted several outsized moves in recent days, appreciating sharply on Thursday and Friday from 38-year lows of 161.96 per dollar, sudden rallies that market participants said had the signs of currency intervention.

Bank of Japan data released on Tuesday suggested Tokyo may have spent 2.14 trillion yen ($13.5 billion) intervening on Friday. Combined with the estimated amount spent on Thursday, Japan is suspected to have bought nearly 6 trillion yen via intervention last week.

The dollar index, which measures the greenback against a basket of currencies, fell 0.49% at 103.70, with the euro up 0.39% at $1.0939.

Against the Japanese yen, the dollar weakened 1.32% to 156.3.

The weaker dollar boosted demand for precious metal, propelling spot gold to an all-time high of $2,477.38 an ounce.

Gold, priced in dollars, has a strong inverse relationship with the U.S. currency, as well as Treasury yields.

The yield on benchmark U.S. 10-year notes rose 0.6 basis points to 4.173%, from 4.167% late on Tuesday.

Softer jobs data and easing inflation has brought Treasury yields down this month by boosting the odds of the impending rate cut.

Elsewhere, oil prices gained, with U.S. crude 1.75% higher at $82.17 a barrel. Brent rose to $84.75 per barrel, up 1.22% on the day.

(Additional reporting by Chuck Mikolajczak and Caroline Valetkevitch, Editing by Sam Holmes, Kim Coghill, Arun Koyyur, Will Dunham and Gareth Jones)