* Trump unhappy with latest Iranian proposal, official

says

* Tech stocks slip on concerns over AI spending boom

* UAE sets date for leaving OPEC, OPEC+

(Updates prices to US market close, adds comment in paragraph

12)

By Rodrigo Campos

NEW YORK, April 28 (Reuters) - Oil prices rose on

Tuesday as investors assessed the stalemate in the Iran conflict

and news that the United Arab Emirates was cutting ties with

OPEC, while concerns that the AI boom was losing momentum

weighed on equity markets.

U.S. bond prices also slid, with yields up on concern over

the effect of high energy prices on inflation.

U.S. President Donald Trump is unhappy with the latest Iranian

proposal ​on resolving the two-month war, a U.S. official said,

dampening hopes for resolution of a conflict that has killed

‌thousands while disrupting energy supplies and fuelling

inflation. The conflict is at an impasse and energy supplies are

still unable to transit freely through the Strait of Hormuz.

The UAE said on Tuesday it was quitting OPEC and OPEC+,

dealing a blow to the oil-exporting groups and their de facto

leader, Saudi Arabia, at a time when the Middle East conflict

has caused a historic energy shock. Oil prices briefly pared

gains on the news, but Brent was last hovering near a three-week

high while WTI broke through $100 per barrel for the first time

since April 13.

"The UAE leaving shows how tough it can be to keep a cartel

together during tough times," said Brian Jacobsen, chief

economic strategist at Annex Wealth Management. "The UAE is

OPEC's third-largest producer and the quota it has is well below

its capacity."

He said that even if the immediate reaction was muted,

"longer-term it gives OPEC a lot less sway over the markets."

U.S. crude rose 3.68% to $99.92 a barrel and Brent

rose to $111.13 per barrel, up 2.68% on the day.

EARNINGS AND AI IN FOCUS

The tech-heavy Nasdaq Composite underperformed other U.S.

indexes as investors questioned whether the artificial

intelligence boom could continue to deliver meaningful returns.

The Wall Street Journal reported that AI heavyweight OpenAI had

missed internal targets for weekly users and revenue, raising

concerns over the ChatGPT parent's ability to support its

massive spending on data centers.

The Dow Jones Industrial Average fell 31.64 points,

or 0.06%, to 49,136.15, the S&P 500 fell 35.13 points,

or 0.49%, to 7,138.78 and the Nasdaq Composite

fell 223.30 points, or 0.90%, to 24,663.80.

Tech stocks linked to artificial intelligence, such as Oracle

and CoreWeave ( CRWV ) as well as chip stocks AMD

and Broadcom, dropped more than 3% each.

Despite the day's declines, the broader index of semiconductor

stocks remains up more than 40% so far this year.

"(OpenAI) is giving investors more food for thought, whether

the growth is slowing and what that means for capex spending,"

said Chuck Carlson, chief executive officer at Horizon

Investment Services in Hammond, Indiana. "You've got major

hyperscalers coming out with results tomorrow, which probably

gives investors even more reason to take a few chips off the

table."

MSCI's gauge of stocks across the globe fell

8.04 points, or 0.53%. The pan-European STOXX 600 index

fell 0.37%, the emerging market stocks gauge was down

0.76% and MSCI's broadest index of Asia-Pacific shares outside

Japan was down 0.7%. Japan's Nikkei index

fell 1% after hitting a record high on Monday.

Investors are also focusing on earnings from U.S. tech giants

Microsoft ( MSFT ), Alphabet, Amazon ( AMZN ), Meta

Platforms ( META ) and Apple ( AAPL ), which will further test

the AI-driven rally.

Higher oil prices continued to lift inflation expectations. The

2-year Treasury note yield, which typically moves in

step with interest rate expectations for the Federal Reserve,

rose 3.1 basis points to 3.836%, compared with 3.805% late on

Monday.

Will Compernolle, macro strategist at FHN Financial, said the

rise in yields was following the rise in oil prices.

"That could really just be from the erratic sentiment ... It

seems like the day-to-day market mood about U.S.-Iran changes

even if the underlying fundamentals are the same," he said.

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

basis point to 4.346%, from 4.336% late on Monday, while on the

long end the 30-year bond yield dipped 0.6 basis

point to 4.9358%, from 4.942%.

The dollar index, which measures the greenback

against a basket of currencies including the yen and the euro,

rose 0.19%. The British pound fell 0.1% against the dollar and

the euro was little changed .

The dollar has been one of the few safe-haven assets during the

Iran conflict, although it has given up a large part of its

March gains in the last few weeks.

BANK OF JAPAN SPLIT ON RATES

The BOJ left short-term rates unchanged at 0.75%, in the

first of several central bank meetings this week that could

provide evidence of the Middle East conflict's economic impact.

The yen briefly strengthened on the view that a rate

hike was now in play, but was last 0.12% lower at 159.6 per

dollar. A breach beyond the 160-per-dollar threshold would put

markets on alert that Tokyo might step in to support its

currency.

The U.S. Federal Reserve, the Bank of England and the European

Central Bank are due to announce decisions later this week.

All are expected to keep rates unchanged but market

attention will be on comments from policymakers on pricing

pressure.