NEW YORK, May 4 ― US stock indexes were set for a lower open as news of PacWest Bancorp exploring strategic options deepened concerns about the health of regional banks, countering optimism from the Federal Reserve's signal of a likely pause in its interest rate hikes.

PacWest Bancorp tumbled 37.2 per cent in premarket trading day after it confirmed it was exploring strategic options, including a sale, after shares of the regional lender and peers got hammered amid fears of a worsening banking crisis.

Regulators seized troubled First Republic Bank and JPMorgan Chase agreed to buy majority of its assets earlier this week, marking the largest US bank failure since the 2008 financial crisis.

Shares of other regional lenders such as KeyCorp, Valley National Bancorp and Zions Bancorp fell between 7.7 per cent and 9.6 per cent today, while Western Alliance Bancorp dropped 13.4 per cent despite noting that it had not experienced unusual deposit outflows following the sale of First Republic.

“PacWest is more evidence that the US banking crisis is not over yet,” said Stuart Cole, chief macro economist at Equiti Capital.

“It (PacWest) does appear that it is struggling, and I would be very surprised if it was not for the same reasons as those before it ... the market is circling all these regional US banks like a vulture, looking which one to pick off next.”

The US central bank yesterday raised interest rates by 25 basis points to the 5.00 per cent-5.25 per cent range and signalled a pause in its policy tightening, giving officials time to assess the recent bank failures, US debt ceiling situation and sticky inflation.

However, US stocks dropped yesterday after Fed Chair Jerome Powell said that it was too soon to say with certainty that the rate-hike cycle was over as inflation remains the chief concern.

US interest rate futures priced in a pause in tightening at the Fed's June and July policy meetings, according to the CME's FedWatch tool, and also factored in a nearly 50 per cent chance of rate cuts at the September meeting.

Although the end of Fed's market-punishing rate-hike cycle may be in sight, uncertainty over stock valuations and the economic outlook are keeping investors on alert for more turbulence ahead.

Major technology and growth stocks such as Meta Platforms Inc, Microsoft Corp and Alphabet Inc edged up today, helped by a fall in US Treasury yields.

The number of Americans filing new claims for jobless benefits increased last week as the labour market gradually softens amid higher interest rates, which are cooling demand in the economy.

Apple Inc shares fell 1.5 per cent, with the iPhone maker set to report quarterly results after the closing bell.

At 8.34 am ET, Dow e-minis were down 68 points, or 0.20 per cent, S&P 500 e-minis EScv1 were down 11.5 points, or 0.28 per cent, and Nasdaq 100 e-minis were down 18.25 points, or 0.14 per cent.

Qualcomm Inc slumped 7.4 per cent after the chip designer's third-quarter forecasts missed estimates.

Paramount Global Inc dropped 17.2 per cent after missing first-quarter revenue estimates as it added fewer subscribers at its flagship streaming service and advertisers cut back on spending. ― Reuters