* Fed minutes show disappointment over data

* US existing home sales fall short of estimates

* Markets turn focus to Nvidia results

* Oil slips again on worries over softening demand

NEW YORK, May 22 (Reuters) - Wall Street turned lower and oil prices fell on Wednesday as investors parsed the minutes from the U.S. Federal Reserve's most recent policy meeting, and looked ahead to Nvidia Corp's earnings release, expected after the bell.

All three major U.S. stock indexes turned decisively lower in afternoon trading, extending their losses after minutes from the U.S. Federal Reserve showed Fed officials were disappointed in recent inflation readings and acknowledged that "disinflation would likely take longer than previously thought."

"'Higher for longer' is the spark for today's pressure on the markets," said Greg Bassuk, CEO at AXS Investments in New York. "The Fed confirmed its worries that it hasn't seen more progress in inflation."

"And that, combined with the investor worries of an over inflated market is fueling the jitters on wall street," Bassuk added.

Mixed quarterly results from retailers Target and TJX raised questions about the resiliency of the U.S. consumer.

But at the forefront of investors' minds are results from megacap chipmaker Nvidia due after regular trading hours, which could further test the recent rally in U.S. stocks which has been largely driven by the promise of AI technology.

With Nvidia results waiting in the wings "there's growing sentiment that Nvidia, the chip sector generally, and the overall market have advanced too high too fast," Bassuk said. "We think the hype around Nvidia is overblown and we think investors would be prudent to look at the stock with a more cautious eye today."

Economic data released on Wednesday showed existing home sales came in below analyst estimates, while hotter-than-expected core inflation data from Britain prompted investors to pull their bets on a Bank of England rate cut next month.

British Prime Minister Rishi Sunak called an election for July 4, which his governing Conservatives are widely expected to lose to the Labour Party.

"Clearly Sunak is hoping that the element of surprise will go in his favour, particularly, on the back of the better inflation data today, but I don't think markets are going to be particularly moved by this," said Jane Foley, head of FX strategy at Rabobank in London. "It doesn't change the fact that the Labour Party is 20 points ahead in the polls."

The Dow Jones Industrial Average fell 287.68 points, or 0.72%, to 39,585.31, the S&P 500 lost 32.27 points, or 0.61%, to 5,289.14 and the Nasdaq Composite dropped 107.10 points, or 0.64%, to 16,725.53.

European shares pulled back as the stronger-than-expected British inflation data dampened the mood, which was already weighed down following a report about possible Chinese tariffs on imported cars.

The pan-European STOXX 600 index lost 0.34% and MSCI's gauge of stocks across the globe shed 0.61%.

Emerging market stocks rose 0.10%. MSCI's broadest index of Asia-Pacific shares outside Japan closed 0.19% higher, while Japan's Nikkei lost 0.85%.

Yields for 10-year Treasury notes edged up from session lows after the release of the Fed minutes.

Benchmark 10-year notes last fell 4/32 in price to yield 4.4276%, from 4.414% late on Tuesday.

The 30-year bond rose 5/32 in price to yield 4.5453%, from 4.554% late on Tuesday.

The dollar advanced against a basket of world currencies while the pound strengthened after Britain's hotter-than-expected core inflation reading.

The dollar index rose 0.27%, with the euro down 0.31% to $1.082.

The Japanese yen weakened 0.27% to 156.61 per dollar, while sterling was last trading at $1.2713, up 0.05% on the day.

Crude prices dropped for the third consecutive session on fears that prolonged restrictive Fed policy could take its toll on demand.

U.S. crude slid 1.39% to settle at $77.57 per barrel, while Brent settled at $81.90 per barrel, down 1.18% on the day.

Gold prices plunged, backing down from recent record highs as investors digested the Fed minutes.

Spot gold dropped 1.8% to $2,377.86 an ounce.

(Reporting by Stephen Culp, additional reporting by Tom Wilson and Amanda Cooper in London; Editing by Emelia Sithole-Matarise and Philippa Fletcher)