* Futures down: Dow 0.3%, S&P 500 0.4%, Nasdaq 0.6%

* Walmart ( WMT ) falls after maintaining annual targets

* Quantum stocks jump as US to invest in the firms in

exchange for stakes

(Update before market open)

By Ragini Mathur and Utkarsh Hathi

May 21 (Reuters) - Wall Street's main indexes were set

to open lower on Thursday as oil prices surged following a

Reuters report that Iran's Supreme ‌Leader Ayatollah Mojtaba

Khamenei ordered the country's near-weapons-grade uranium not be

sent abroad, dimming hopes for progress in talks between

Washington and Tehran.

Brent crude futures jumped 1.7% to $106.82 a barrel.

Oil had traded lower earlier in the session, extending

losses from Wednesday, on optimism that diplomatic efforts could

ease tensions. But the Reuters report later suggested Iran was

hardening its position on one of Washington's key demands,

reviving concerns about a prolonged disruption around the Strait

of Hormuz, a critical route for global oil supplies.

The yield on the benchmark U.S. 10-year Treasury note rose

to 4.611%, resuming its recent climb after snapping a three-day

run of gains on Wednesday. A lack of meaningful progress towards

reopening the strait has added to inflation concerns, pushing up

yields and weighing on equities.

Investors also parsed a fresh batch of corporate earnings.

Walmart ( WMT ) dipped 2.9% in premarket trading after the

largest retailer globally maintained annual targets and forecast

second-quarter profit below estimates against a strained U.S.

economic backdrop.

"The guidance (from Walmart ( WMT )) is what has caused investors to

be concerned that finally we are seeing the effects of high oil

prices and inflation on retail expectations. So that's what's

putting some pressure on stocks today," said Sam Stovall, chief

investment strategist, CFRA Research.

Shares of Nvidia ( NVDA ), the world's most valuable

company, edged down 0.8%, even after the AI heavyweight forecast

second-quarter revenue above Wall Street estimates and announced

an $80 billion share repurchase program.

Its stock has jumped almost 20% so far this year but the

pace of growth has slowed as investors believe Nvidia ( NVDA ) will face

tougher competition, not only from Big Tech but also chip rivals

including Intel ( INTC ) and Advanced Micro Devices ( AMD ).

At 8:54 a.m. ET, Dow E-minis were down 153 points,

or 0.31%, and S&P 500 E-minis were down 27.5 points, or

0.37%. Nasdaq 100 E-minis were down 166.75 points, or

0.57%.

Investors also monitored SpaceX after the company unveiled

its IPO filing on Wednesday, giving the market its first glimpse

into how much billionaire Elon Musk is spending on AI as he bets

on transforming the rocket maker into a broader AI-led business.

On the economic front, the number of Americans filing new

applications for unemployment benefits fell last week, pointing

to continued labor-market resilience and giving the Federal

Reserve room to keep its focus on inflation risks.

Business activity surveys due at 9:45 a.m. ET could provide

further clues on the health of the U.S. economy.

IBM ( IBM ) climbed 5.8% as the Trump administration is

awarding grants to a handful of companies, including IBM ( IBM ), that

are focussed on quantum computing in exchange for stakes in some

of them.

GlobalFoundries ( GFS ) was up 13.4%, D-Wave Quantum ( QBTS )

jumped 14.5%, Rigetti Computing ( RGTI ) gained 13.2%

and Infleqtion ( INFQ ) added 21.5%.

Intuit shares fell 15.9% after the software maker

lowered the annual revenue forecast for its tax-filing software,

TurboTax, and said it would cut 17% of its full-time workforce.