Portugal Colonial - European stocks rise as oil tumbles, while tech worries weigh on New York

European shares were higher, while they were weighed down in the US by renewed concerns that tech valuations are too frothy.

"Questions about Nvidia's impending investment in OpenAI have rattled the AI landscape," said Patrick J. O'Hare at Briefing.com. Reports suggest that the investment will be "nothing like" the $100 billion previously discussed.

In New York, the Dow was little changed in morning trading, while the wider S&P and the tech-heavy Nasdaq were down marginally.

Shares on Asian bourses had slumped earlier in the day on tech concerns.

But in Europe, the main indexes were all almost a percentage point higher at mid-afternoon, despite heavy losses by heavyweight miners, as oil fell and the dollar steadied.

Gold and silver began tumbling Friday on news that US President Donald Trump had chosen Kevin Warsh to become new head of the US Federal Reserve, who is seen as more hawkish than some of the other names mentioned.

Gold steadied Monday, easing 0.4 percent to $4,735.1 an ounce, well below the record highs above $5,500 it hit last week.

Silver was up four percent at $81.78, but well below its recent record high above $120 reached last week.

"Many investors bought gold and silver as protection against the volatile geopolitical backdrop, yet they've learned the hard way these assets can also be volatile themselves," said Russ Mould, investment director at AJ Bell.

Traders regard Warsh, a former Morgan Stanley investment banker and Fed governor, as the toughest inflation fighter among the final candidates, raising expectations that his monetary policy would underpin the greenback.

The choice also eased concerns about the Fed's independence following a series of attacks on incumbent Jerome Powell over his reticence to cut rates as quickly as the president wanted.

Oil prices meanwhile plunged on easing US-Iran tensions.

Both main crude contracts shed more than five percent at one point after Trump said he was hopeful of reaching a deal with Tehran.

Washington has hit out at the country's leadership in recent weeks over its deadly response to anti-government protests, with Trump threatening military action.

He has also pushed for an agreement over Iran's nuclear programme.

Monday's volatility across markets comes as investors look ahead to more big earnings due this week alongside interest-rate decisions and US jobs data.

After a strong January fuelled by artificial intelligence bets, stocks went into reverse last week as traders resumed questioning the wisdom of the vast sums pumped into the sector and when they will see returns.

That has also raised fears of a tech bubble that could soon pop.

The latest round of selling came after Microsoft last week announced a surge in spending on AI infrastructure, reviving concerns companies could take some time before seeing a return on their investments.

Seoul, which has hit multiple records this year thanks to its big tech weighting, plunged more than five percent on Monday, with chip giant SK hynix shedding eight percent and market heavyweight Samsung off more than six percent.

Tokyo, also home to several big-name tech firms, shed more than one percent, as did Taipei, where chip giant TSMC is listed.

- Key figures at around 1435 GMT -

New York - Dow: FLAT at 48,8899.65 points

New York - S&P 500: DOWN 0.2 percent at 6,927.41

New York - Nasdaq Composite: DOWN 0.3 percent at 23,390.07

London - FTSE 100: UP 1.0 percent at 10,324.68

Paris - CAC 40: UP 0.9 percent at 8,200.22

Frankfurt - DAX: UP 0.8 percent at 24,747.38

Tokyo - Nikkei 225: DOWN 1.3 percent at 52,655.18 (close)

Hong Kong - Hang Seng Index: DOWN 2.2 percent at 26,775.57 (close)

Shanghai - Composite: DOWN 2.5 percent at 4,015.75 (close)

Euro/dollar: DOWN at $1.1812 from $1.1856 on Friday

Pound/dollar: UP at $1.3701 from $1.3688

Dollar/yen: UP at 155.34 yen from 154.64 yen

Euro/pound: DOWN at 86.62 pence from 86.63 pence

Brent North Sea Crude: DOWN 4.1 percent at $66.50 per barrel

West Texas Intermediate: DOWN 4.1 percent at $62.49 per barrel

R.Veloso--PC