* Samsung sees 19-fold increase in April-June operating

profit

* Nasdaq 100 E-minis down 1.2%, S&P 500 E-minis dip 0.3%

* Brent crude up 1% after US-Iran peace talks appeared to

stall

(Updates prices)

By Amanda Cooper

LONDON, July 7 (Reuters) - Global stocks fell on Tuesday as

technology shares slid despite blockbuster results from Samsung

Electronics ( SSNLF ), with investors remaining concerned about the

sustainability of the AI-driven rally, while oil prices rose on

renewed Middle East tensions.

Samsung Electronics ( SSNLF ) forecast a 19-fold jump in

April-June operating profit to 89.4 trillion won ($58.4

billion), a third straight quarter of record operating profit

for the world's largest memory-chipmaker.

Rather than reassuring investors, the results triggered

heavy selling in Samsung and rival SK Hynix shares, weighing on

South Korea's Kospi and other technology-heavy Asian

markets. Investors have increasingly questioned whether profit

growth linked to artificial intelligence can be sustained if

supply bottlenecks in key components such as memory chips ease.

"This is a record for Samsung, but rather than placate the

markets, these strong results have led to fears that the AI chip

sales boom cannot be sustained," Kathleen Brooks, research

director at XTB, said.

Morgan Stanley said in a note dated Monday that recent weakness

in U.S. semiconductor stocks signalled a broadening of market

gains, with investors likely to turn towards AI hyperscalers as

well as consumer discretionary, transport and biotechnology

shares.

SK Hynix is due to join the Nasdaq this week in a $28 billion

listing, one of the world's largest new share sales, as the

chipmaker seeks to capitalise on the AI boom.

Its shares, which were up as much as 350% this year at their

peak two weeks ago, have since fallen about 30% amid a broader

sell-off in global chip stocks.

In Europe, where exposure to volatile AI-linked stocks is more

limited, the STOXX 600 slipped 0.1%, as losses in

semiconductor and tech stocks offset gains in in oil and gas

shares. Energy stocks got a lift from crude prices edging higher

on the back of signs that U.S.-Iran peace talks were losing

momentum.

Adding to market concerns, Iran's Revolutionary Guards fired at

least two missiles at commercial ships transiting the Strait of

Hormuz on Monday, Axios reported, citing two U.S. officials. The

ships suffered significant damage, but there were no casualties,

the report said.

Brent crude futures rose about 1% to $72.72 a barrel.

Futures on the S&P 500 were down 0.2%, while those on

the Nasdaq 100 slid 1.1%.

NATO MEETING SET TO START IN TURKEY

U.S. President Donald Trump, who has pressed Europe to boost

defence spending and clashed with European leaders over the Iran

war and Greenland, is due to attend a NATO meeting in Turkey

beginning on Tuesday.

Trump said on Monday the U.S. would either reach a deal with

Iran or "finish the job," renewing his threat of military action

as Tehran projects defiance following the funeral of supreme

leader Ayatollah Ali Khamenei.

In currency markets, the dollar index, which tracks the

U.S. currency against six others, was little changed at 100.9.

The euro was flat around $1.143, as was the pound

at $1.339.

The yen clawed above 40-year lows to trade a touch

stronger on the day at 161.9 to the dollar. Traders were alert

for intervention given signs of a possible shift in strategy by

Japanese authorities.

The yield on benchmark U.S. 10-year notes was up 1

basis point at 4.49%, ahead of the release on Wednesday of the

minutes of the Federal Open Market Committee's latest meeting.

These may give investors more of a steer on how new Federal

Reserve chair Kevin Warsh is approaching monetary policy.

(Additional reporting by Satoshi Sugiyama in Tokyo; Editing by

Mark Potter and Kevin Liffey)