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* Fed sees 25 bp hike this year, 50 bp cuts in 2024

* Fed's projections see inflation approaching goal at end of 2025

* Klaviyo jumps in debut

* Indexes: Dow up 0.43%, S&P 500 off 0.09%, Nasdaq down 0.36%

Sept 20 (Reuters) - Wall Street oscillated after the U.S. Federal Reserve held key interest rates unchanged as widely expected, and revised economic projections higher, even as Chairman Powell warned the battle against inflation was far from over.

All three major U.S. stock indexes whipsawed in the wake of announcement and the accompanying Summary Economic Projections (SEP) and dot plot, which sees an additional 25 basis point rate hike this year, peaking in the 5.50%-5.75% range.

The projections also called for 50 basis points of rate cuts next year.

“There were no surprises," said Peter Cardillo, chief market economist at Spartan Capital Securities in New York. "(The Fed) sees one more rate hike...and sees interest rates remaining elevated a bit longer than previously stated, and that’s cutting into the market."

The updated projections see the Fed funds target rate edging down to 5.1% by the end of next year, and to 3.9% by the end of 2025.

At 2:48 p.m. ET, the Dow Jones Industrial Average rose 148.43 points, or 0.43%, to 34,666.16, the S&P 500 lost 3.86 points, or 0.09%, to 4,440.09 and the Nasdaq Composite dropped 49.03 points, or 0.36%, to 13,629.15.

Since the Fed embarked on its current tightening cycle in March, core inflation has cooled. But the progress of its descent toward the central bank's target has been slow and uneven.

The SEP forecasts inflation to drop to 3.3% by year-end, and to approach the central bank's average annual 2% target.

At the subsequent press conference, Fed Chairman Jerome Powell tempered rosier economic projections with a warning that inflation has a long way to go before reaching that target.

Powell "doesn’t want the market to get complacent. He wants the markets to know he still needs to see inflation to reach the 2% target," Cardillo added.

Among the 11 major sectors of the S&P 500, interest rate sensitive communication services and technology suffering the largest percentage losses.

Marketing automation company Klaviyo jumped 13.5% in its debut on the New York Stock Exchange, the third recent initial public offering in recent days, following Arm Holdings and Maplebear Inc.

Maplebear was last down 5.7%, on track to join other new entrants in failing to hold on to their strong gains on debut. Arm Holdings was down 3.9%.

Pinterest added 5.0% after the image-sharing firm announced a share buyback of up to $1 billion.

Coty gained 5.1% after the CoverGirl parent hiked its annual core sales forecast.

Advancing issues outnumbered declining ones on the NYSE by a 2.53-to-1 ratio; on Nasdaq, a 1.38-to-1 ratio favored advancers.

The S&P 500 posted 14 new 52-week highs and 6 new lows; the Nasdaq Composite recorded 38 new highs and 187 new lows. (Reporting by Stephen Culp; Editing by David Gregorio)