(Adds preliminary closing details, analyst comment)

By Sinéad Carew and Lisa Pauline Mattackal

Oct 15 (Reuters) - Wall Street's major stock indexes

closed lower on Tuesday, with the technology-heavy Nasdaq

leading declines as chip stocks sold off on fears of weak demand

while energy shares fell with oil prices.

Earnings reports were a mixed bag with mostly positive

reactions to financial services results contrasting with a slump

in shares of UnitedHealth ( UNH ) after the health insurer

forecast 2025 profit below Wall Street estimates.

Nasdaq came under particular pressure from market

heavyweight Nvidia ( NVDA ), the leading chip maker for

artificial intelligence. Its shares fell after a record-high

close on Monday and a media report that the Biden administration

is considering capping AI chip exports by U.S. companies.

Chip stocks lost ground broadly after results of

chip-equipment-maker ASML Holdings showed downbeat

expectations for 2025 sales. ASML's U.S.-listed shares

tumbled and dragged down the Philadelphia semiconductor index

.

"There seems to be a lot more stress concentrated in chips.

This is putting downward pressure on technology as a sector,"

said Kevin Gordon, senior investment strategist at Charles

Schwab ( SCHW ).

But while Gordon saw weaker-than-expected earnings as an

excuse to sell off chip stocks, he was encouraged that there

were roughly as many stocks advancing as declining on the

Nasdaq.

"It's not a broad-based washout," he said, noting that

stocks that were selling off on the day had previously

outperformed. "It's indicative of megacap stocks pulling down

the indexes."

The energy industry index was under pressure as

crude prices fell on weaker demand expectations after a media

report suggested Israel would not strike Iranian oil targets.

According to preliminary data, the S&P 500 lost 41.98

points, or 0.72%, to end at 5,817.87 points, while the Nasdaq

Composite lost 180.26 points, or 0.97%, to 18,322.42.

The Dow Jones Industrial Average fell 320.46 points, or

0.77%, to 42,733.92.

Both the Dow and the S&P 500 registered record closing highs

in the previous session.

In the financial sector, Bank of America ( BAC ) shares rose

following a third-quarter profit beat, while Charles Schwab ( SCHW )

shares climbed after beating estimates. However,

Citigroup ( C/PN ) shares fell after its results.

Bucking the trend of tech stock declines, Apple ( AAPL )

advanced, earlier touching a record high.

Also in individual stocks, Walgreens Boots Alliance ( WBA )

rallied sharply after narrowly beating Wall Street's lowered

estimates for fourth-quarter adjusted profit and announcing

plans to shut 1,200 stores to cut costs.

Investors will watch in coming days for the next batch of

earnings as well as key economic data, including monthly retail

sales and industrial production figures.

Earlier on Tuesday, San Francisco Fed President Mary Daly

said that even after September's interest-rate cut, policymakers

were still working to bring down inflationary pressures.

Traders are pricing in a roughly 98% chance the Fed will cut

interest rates by 25 basis points in November, according to

CME's FedWatch.