Updates to midafternoon trading, adds analyst comment

By Stephen Culp and Medha Singh

NEW YORK, June 4 (Reuters) - Wall Street advanced on Thursday as progress toward ending the Iran war buoyed investor sentiment, while disappointing results from Broadcom led a chip selloff that held the Nasdaq's gains in check.

The blue-chip Dow touched a record high, with a boost from healthcare .SPXHC and financial stocks .SPSY, but the gains of the S&P 500 and the Nasdaq were more muted.

Chipmaker Broadcom AVGO.O missed revenue expectations, sending its shares tumbling 11.2% and casting a pall over the AI frenzy, which has sent chip stocks .SOX up nearly 95% so far this year.

"Broadcom is down, but Nvidia and Taiwan Semiconductor are up," said Oliver Pursche, senior vice president at Wealthspire Advisors in New York. "This is a great example of rational exuberance in the sector, where the right companies are being rewarded, and if you stumble or have a bad quarter or a mediocre outlook for the remainder of the year, you get punished."

The U.S. House of Representatives passed a measure on Wednesday that would block President Donald Trump from continuing the war on Iran.

Additionally, a U.S.-mediated ceasefire agreement between Israel and Lebanon, an essential condition of an Iranian agreement to a peace deal, bolstered optimism of a near-term resolution to the war. But the truce was rejected by the pro-Iran Hezbollah, which said it would not withdraw troops from Lebanon.

A drop in front-month crude futures reflected hopes that tanker traffic through the crucial Strait of Hormuz could shortly resume.

"Congress has effectively limited the president's war powers abilities," Pursche added. "The U.S. is very incentivized to come up with a deal and to end this, because Iran holds the cards and they have effectively said they're going to keep a stranglehold on the Strait of Hormuz" until a deal is reached.

On the economic front, initial jobless claims unexpectedly rose 6.1%, and first-quarter labor costs and productivity were revised sharply lower. A report from Challenger, Gray and Christmas showed layoffs announced by U.S. corporations jumped 11% in May to 97,006, of which 39.8% was attributed to AI.

The Dow Jones Industrial Average .DJI rose 809.88 points, or 1.60%, to 51,496.83, the S&P 500 .SPX gained 39.74 points, or 0.53%, to 7,593.42 and the Nasdaq Composite .IXIC gained 60.69 points, or 0.23%, to 26,915.12.

Among the 11 major sectors of the S&P 500, healthcare and financial stocks boasted the biggest percentage gains, while technology shares .SPLRCT were down the most.

Chipmaker Marvell Technology MRVL.O gained 5.6%, while Advanced Micro Devices AMD.O, Micron Technology MU.O and Qualcomm QCOM.O fell between 1.9% and 4.1%.

The healthcare sector got a boost from UnitedHealth UNH.N, which jumped 5.0% after Bank of America raised its rating on the healthcare conglomerate's shares to "buy."

The financial index's rebound followed a sharp selloff in the previous session due to revived concerns over private credit.

Blackstone BX.N became the latest asset manager to cap withdrawals from its flagship private credit fund following a rise in redemption requests. Its shares jumped 7.1%.

Cybersecurity firm CrowdStrike CRWD.O slumped 4.5% after reporting an increase in quarterly operating expenses.

An investor roadshow for Elon Musk-led SpaceX SPCX.O began on Thursday ahead of its market debut on June 12. It aims to raise $75 billion in a record IPO that would value it at $1.75 trillion.

Advancing issues outnumbered decliners by a 1.97-to-1 ratio on the New York Stock Exchange. There were 206 new highs and 121 new lows on the NYSE.

On the Nasdaq, 3,049 stocks rose and 1,654 fell as advancing issues outnumbered decliners by a 1.84-to-1 ratio.

The S&P 500 posted 21 new 52-week highs and 7 new lows while the Nasdaq Composite recorded 77 new highs and 85 new lows.