(Updates with preliminary closing prices)

By Sinéad Carew and Shashwat Chauhan

May 14 (Reuters) - The S&P 500 closed slightly higher

after flitting between gains and losses during Wednesday's

session as investors waited for the next batch of economic data

after a robust start to the week spurred by soft inflation data

and a U.S.-China tariff truce,

Investors were watching out for more trade developments

while President Donald Trump toured the Gulf states and secured

$600 billion in commitments from Saudi Arabia. Some U.S. tech

companies rallied after the administration announced

artificial-intelligence-related deals in the Middle East on

Tuesday.

"There's overhanging uncertainty about what world leaders,

including President Trump are going to say about trade," said

Tim Ghriskey, senior portfolio strategist at Ingalls & Snyder in

New York, noting that while earlier tariff policies were on

pause there were no final deals in place.

"The recent announcements have been good and that caused a

huge rally, but we still have uncertainty," he said.

U.S. stocks had gained ground sharply on Monday and advanced

again on Tuesday after the United States and China hit pause for

90 days on their fierce tariff dispute.

And it had also helped that data released on Tuesday showed

U.S. consumer prices rebounded moderately in April.

Prior to this week, the U.S. announcement of a 90-day tariff

pause on April 9 for countries other than China and a limited

U.S.-UK trade agreement last week had also helped equities.

U.S. Federal Reserve Vice Chair Philip Jefferson said on

Wednesday that while recent inflation data pointed to progress

towards the Fed's 2% inflation goal, the outlook was now

uncertain. Chicago Fed President Austan Goolsbee said the data

did not necessarily reflect the impact of rising tariffs.

According to preliminary data, the S&P 500

gained 5.56 points, or 0.09%, to end at 5,892.11 points,

while the Nasdaq Composite gained 132.91 points, or

0.70%, to 19,142.99. The Dow Jones Industrial Average

fell 95.43 points, or 0.23%, to 42,045.00.

Fed Chair Jerome Powell is slated to speak on Thursday, and

his comments will be closely watched for clues on how the

central bank plans to proceed with monetary policy easing.

With Wednesday being a relatively quiet day for economic

data, Andrew Graham, managing partner and founder of Jackson

Square Capital, said investors were holding steady before

April's Producer Price Index (PPI) and retail sales readings due

on Thursday morning.

"People are looking for any sort of evidence that the tariff

situation has leaked into the real economy," said Graham, but

with 90-day pauses to tariff policies in place, he said he is

less concerned about April's data readings.

"You're at a good news is good, but bad news gets a pass

phase," he said.

Megacap and growth stocks rose, with Nvidia ( NVDA ) among

the top index boosts. Chip designer Advanced Micro Devices ( AMD )

shares rose after it approved a $6 billion share buyback

program.

Boeing ( BA ) shares rose after state carrier Qatar Airways

signed a deal to purchase jets from the U.S. planemaker during

Trump's visit to Doha.

In individual stocks, American Eagle Outfitters ( AEO )

shares lost ground after the apparel company withdrew its annual

forecasts, citing tariff-fueled economic uncertainty.