June 10 (Reuters) - U.S. stock index futures fell on Wednesday as technology stocks extended losses, while renewed tensions between the U.S. and Iran weighed on sentiment ahead of a key inflation report.

Volatility has picked up across stock markets in recent days, as investors contend with a widening array of risks, including high valuations in the tech sector, escalating tensions in the Middle East and expectations that the Federal Reserve may need to hike interest rates to curb inflation.

Nvidia ( NVDA ), Broadcom ( AVGO ) and Micron Technology ( MU ) fell between 2% and 3.6% in premarket trading, with losses picking up again after a brief rebound on Monday.

Technology and AI stocks retreated steeply on Friday as Broadcom's ( AVGO ) disappointing outlook fueled concerns over stretched valuations in chipmakers.

"The tech sector is coming under pressure from a combination of higher rate expectations, which lowers the current value of more distant profits, and anxiety over elevated valuations and uncertainties over the monetization of AI," said Mark Haefele, chief investment officer at UBS Global Wealth Management.

"Investors' positioning in parts of the sector may have also become extended after a strong rally."

At 05:29 a.m. ET, Dow E-minis were down 329 points, or 0.65%, and S&P 500 E-minis were down 56 points, or 0.76%. Nasdaq 100 E-minis were down 340.25 points, or 1.17%.

The U.S. military carried out strikes on Iranian targets after President Donald Trump vowed to retaliate against the downing of a U.S. Apache attack helicopter - marking a fresh escalation that risks unraveling the fragile ceasefire between Washington and Tehran.

Oil prices were largely unchanged, with Brent crude trading above $91 a barrel. [O/R]

Attention now turns to May consumer price data, due at 8:30 a.m. ET. The report will be closely watched for clues on how rising energy costs, due to the Iran conflict, are feeding into inflation, especially after last week's hotter-than-expected jobs report fueled concerns about potential Fed rate hikes.

The CPI likely increased 4.2% in the 12 months through May, according to a Reuters survey of economists. That would be the largest annual rise since April 2023 and would follow a 3.8% advance in April.

The much-hyped $1.75 trillion listing of SpaceX on Friday, targeting a record $75 billion raise, could also pressure U.S. stocks as concerns mount over excessive optimism in the tech sector.

Among other movers, Super Micro Computer fell 8.5% after announcing plans to raise $7 billion through a series of equity and equity-linked financing transactions to fund component purchases for its growing AI server demand.

Nike's shares were down 1.6% after RBC downgraded the stock rating to "sector perform" from "outperform".

(Reporting by Joel Jose in Bengaluru; Editing by Shinjini Ganguli)