GLOBAL MARKETS-Stocks lower, gold settles higher as Trump's tariffs spread uncertainty

(Updates prices throughout with U.S. market close, adds gold settlement)

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Wall Street stocks fall and gold rises on US tariff uncertainty

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Trump announces 15% tariff after Supreme Court ruling

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Investors try to work out winners and losers from new regime

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US Treasury yields fall

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Oil prices settle lower

By Chibuike Oguh and Harry Robertson

NEW YORK/LONDON, Feb 23 (Reuters) - Global stocks were lower ?on Monday, dragged down by losses on Wall Street and ?in European equities as fresh uncertainty over U.S. trade policy erupted following President Donald Trump's new global tariff in the wake of a Supreme Court ruling.

The U.S. Supreme ?Court struck down Trump's emergency tariffs on Friday, leading the president to quickly announce a new 10% rate on ?all U.S. imports, only to then lift it to 15% on Saturday. The new tariffs ?are based on Section ?122 of the Trade Act of 1974.

The Dow Jones Industrial Average fell 1.66%, the S&P 500 fell 1% and the Nasdaq Composite fell 1.1%.

"We are giving ?up roughly half of Friday's gain due mostly to the shift ?to 15% on Section 122 versus 10% announced Friday, reminding us that uncertainty remains high," said Mark Hackett, chief market strategist at Nationwide in Philadelphia.

U.S. stock markets are also set to be ?tested later this week by earnings from Nvidia (NVDA), which ?are likely to ?cause waves given that the chip designer makes up almost 8% of the S&P 500 index. Nvidia (NVDA) finished up 0.91%.

The pan-European STOXX 600 index fell 0.45%. Germany's DAX lost 1% but Britain's FTSE 100 ended flat. ?MSCI's gauge of stocks across the globe fell 0.74%.

U.S. gold futures for April delivery settled 2.8% higher at $5,225.60. Spot ?gold eased 0.07% to $5,227 an ounce and silver rose 0.02% to around $88.19 per ounce .

U.S. Treasury yields were lower across the board. The yield on benchmark U.S. 10-year notes fell 5.2 basis points to 4.033%. The 2-year note yield fell 3.8 basis points to 3.422%.

TARIFF DILEMMA

Trump on Monday warned countries against backing away from recently negotiated trade deals with the U.S. after ?the Supreme Court's ?decision, saying that he would hit them with much higher duties under different trade laws.

It ?was unclear when the new tariffs would be imposed, what might be excluded and whether every country would face ?a 15% rate. Some, including the UK and Australia, had 10% tariff rates under the former rules, while many countries in Asia had higher rates.

The Yale Budget Lab said the overall average effective tariff rate would stand at 13.7% after Trump's announcement on Saturday, down from 16% - the highest since 1936 - before the Supreme Court's ruling.

It added that it expected the 15% tariffs would expire after 150 days, following the Trade Act of 1974, under which they will be set. If so, the average rate would fall to 9.1%.

The U.S. ?dollar was weaker against the euro, Japanese yen and Swiss franc. The dollar fell 0.22% to 154.71 against the Japanese yen. Against the Swiss franc, the dollar weakened 0.19% to 0.774.

The euro was up 0.06% at $1.1787.

Brent crude futures settled down 0.38% ?to $71.49 while U.S. crude oil futures fell 0.26% to $66.31.

(Reporting ?by Chibuike Oguh in New York and Harry Robertson in London; Editing by Ros ?Russell, Aurora Ellis and Nia Williams)