(BSS/AFP) - Tech firms diverged Thursday with a mixed bag of results for some of the AI sector`s big beasts tempering the recent spurt of optimism amid growing anxiety about companies` investment and debt.

Markets enjoyed a healthy run-up in the previous two days as traders welcomed strong reports from South Korean chip titan SK hynix and a highly impressive IPO filing from Claude-creator Anthropic.

That helped steady nerves among investors who have started to question the vast sums pumped into the AI build-out and when they will see returns, with the spike in borrowing costs compounding concerns.

But uncertainty crept back in Asia on Thursday after Samsung Electronics` 107.4 trillion won ($80.5 billion) third-quarter operating profit fell short of estimates, even as it represented a breathtaking 783 percent year-on-year jump.

The reading was also the first time any tech company had recorded quarterly operating profit of more than 100 trillion won, Samsung said.

That came after Wall Street titan Alphabet reported lower-than-expected profit and a slowdown in its advertising business.

Alphabet dived 10 percent in after-hours trade, while Samsung lost more than five percent in Asian trade -- showing that traders have set a high bar for firms` earnings.

Still, Microsoft posted forecast-topping revenue and profit, fuelled by its Azure cloud computing division, and Oracle issued a healthy revenue forecast.

And Moody`s Ratings warned that the elevated interest rate environment could pose problems.

"With interest rates much higher in many global regions than they were in 2021, refinancing risk will become more visible as loans originated in 2020-22 approach maturity," it said in its latest Private Credit Quarterly.

"These vintages were underwritten when rates were low and competition was intense, often with higher leverage and more aggressive terms.

"Even in the absence of additional rate hikes, refinancing pressures are likely to challenge weaker borrowers with 2020-22 vintage loans, with not all emerging unscathed."

Among tech firms in Asia, SK hynix rose more than one percent to build on its strong showing this week, while Japan`s Kioxia and Advantest were also well up, but Tokyo Electron and SoftBank retreated along with Taipei-listed TSMC.

Broader markets fluctuated, with Japan`s Nikkei up along with Sydney, Singapore, Wellington and Manila.

But Seoul sank nearly three percent, with Hong Kong, Shanghai, Taipei and Jakarta also down.

There appeared little major reaction to the Federal Reserve`s widely expected decision to hold interest rates, as it cited the need for more data in the fight against inflation, which has held stubbornly above officials` two-percent target for five years.

Two dissenting members of the panel voted for an immediate interest rate increase.

Bank chief Kevin Warsh said policymakers needed more information in the coming weeks to "determine the policy stance appropriate to ensure a timely return of inflation to the two-percent goal".

Oil prices dipped after Wednesday`s rally, though they remain above $100 as reports say the United States is planning to mount a new military attack in Iran after the US midterm elections.

Investors are keeping track of efforts in Israel to form a new government after Prime Minister Benjamin Netanyahu and the opposition were tied in this week`s general election.

The outcome of negotiations could play a major role in the future of the Iran war.

- Key figures at around 0230 GMT -

Tokyo - Nikkei 225: UP 0.3 percent at 64,131.28 (break)

Seoul - Kospi: DOWN 2.9 percent at 5,837.65

Hong Kong - Hang Seng Index: DOWN 0.1 percent at 23,079.25

Shanghai - Composite: DOWN 0.8 percent at 3,653.99

West Texas Intermediate: DOWN 1.2 percent at $101.57 per barrel

Brent North Sea crude: DOWN 0.9 percent at $114.32 per barrel

Euro/dollar: UP at $1.1156 from $1.1154 on Wednesday

Pound/dollar: UP at $1.3332 from $1.3320

Dollar/yen: DOWN at 157.64 yen from 158.03 yen

Euro/pound: DOWN at 83.68 pence from 83.71 pence

New York - Dow: UP 0.2 percent at 52,475.10 (close)

London - FTSE 100: UP 0.1 percent at 10,694.50 (close)