(Updates to U.S. market open, recasts throughout, adds details

of tech earnings, updates headline, adds more details)

* Oil hits $100 on increasing shipping disruptions in the

Middle East

* US stocks dip after Google, Tesla both burn through cash

in latest quarter

* ECB holds rates steady, hawkish tone sends rates higher

* Yen languishing at 40-year lows

By Lawrence Delevingne and Marc Jones

July 23 (Reuters) - Oil prices spiked to $100 a barrel for

the first time since May, major tech giants knocked U.S. stocks

lower, and Europe's borrowing costs spiked to long-term highs in

an unsettling day across markets on Thursday.

Brent crude jumped 6% to $100.50 a barrel following

attacks on tankers in the Red Sea that choked off a second

crucial Middle East artery for global oil supplies alongside

Iran's near-closure of the Strait of Hormuz. This marks the

first time the international oil benchmark has hit that level

since late May as the U.S.-Iran war has heated up again.

The Iran-aligned Houthis struck two Saudi oil tankers as part of

a naval blockade on Saudi Arabia, sending prices higher as the

brief cessation of hostilities between Iran and the U.S. recedes

in the rear-view mirror.

The U.S. military carried out a new round of strikes on

Iran, marking a 12th successive night of American attacks, and

prompting further Iranian retaliation. The White House has

threatened additional attacks on Iranian infrastructure and key

locales for its nuclear facilities.

Wall Street was on the back foot after Alphabet and

Tesla - the first two of the so-called "Magnificent

Seven" megacap companies to report this season - spooked

investors as both burned through cash in their most recent

quarter due to their big spend on AI infrastructure.

Tesla shares tumbled 12% on Thursday as it posted its first cash

burn in two years. Alphabet fell about 7% after the Google

parent also burned through cash and said it would ramp up AI

spending by another $15 billion to $200 billion for the year.

Investors have rewarded the so-called hyperscalers with lofty

valuations on expectations of big revenue gains, but some are

now outspending their operating cash flow.

The Dow Jones Industrial Average fell 1%, the S&P 500

lost 1%, and the Nasdaq Composite slid around

1.9%

EUROPEAN BORROWING COSTS RISE

Europe's government borrowing costs rose to long-term highs

as reignited inflation worries prompted some hawkish signals

from the European Central Bank, even as the bank held rates

steady.

European share markets also fell after an earnings miss from

chipmaker STMicroelectronics sent its shares tumbling

18%. The pan-European STOXX 600 index fell 1.1%.

Germany's 10-year Bund yield, the benchmark for euro zone

borrowing costs, rose above 3.2% for the first time since 2011 -

back when oil was also on a tear and the bloc's debt crisis was

about to break out again.

"Uncertainty remains high and the full inflationary impact

of the energy shock has yet to play out," the ECB said as it

held rates at 2.25%, having lifted them in June.

"The Governing Council is therefore closely monitoring the

intensity and duration of the shock, as well as its indirect and

second-round effects," the ECB added.

Markets had bet on just a one-in-five chance of another

interest rate hike at the meeting. They do, however, see a

four-in-five chance of a hike at the next one in September.

"The messaging remained unchanged and open," Morgan Stanley's

analysts said on the ECB's policy statement. "We maintain our

call for another rate hike in September, if energy prices remain

elevated."

Asian markets gained overnight. The KOSPI

surged more than 4% in Seoul, led by 4.8% and 3.7% respective

gains for SK Hynix ( SKHY ) and Samsung. Tokyo's

Nikkei and Hong Kong's Hang Seng also ticked

higher.

YEN SLIPS BACK TO 40-YEAR LOW

The euro dipped back below $1.14 following the ECB

decision.

The oil price rise and the continent's scorching summer weather

this month look set to hit harvests and push up food prices,

while low water levels on key rivers could create awkward

shipping bottlenecks.

Elsewhere, the Japanese yen was back at a 40-year low

versus the dollar after a brief lift prompted by a Bloomberg

report on Wednesday that Bank of Japan officials were open to

raising rates at a faster pace, faded.

Japan's BOJ-sensitive two-year government bond yield touched a

31-year high in Tokyo on the oil moves and rate hike talk, while

Japan's finance minister had issued his latest verbal warning

about possible FX market intervention.

The dollar index, which measures the greenback against a

basket of currencies including the yen and the euro, rose about

0.3%.