(Updates with index/price moves and company news from the first paragraph.)

US equity indexes were mixed in midday trading on Monday amid gains in government bond yields and higher crude oil prices as hopes faded for a quick reopening of the Strait of Hormuz, the chokepoint for about a fifth of global oil and natural gas flows.

The Nasdaq Composite slipped 0.3% to 26,614.4, with the Dow Jones Industrial Average down 0.3% to 53,905.1. The S&P 500 was little changed at 7,755.6.

Energy and healthcare led the gainers while real estate, technology and utilities were among the steepest decliners.

Shares of Chevron (CVX) were up 4%, the biggest gainer on the Dow.

President Donald Trump signaled a US emphasis on increasing economic pressure on Iran, saying that Washington is "low-keying" negotiations with the country, CNN reported.

Iran said it was nearing a final pact with Oman to define new shipping lanes between them through the Strait of Hormuz, but reiterated that the US must meet other conditions -- compensation and an end to sanctions and military threats -- before the critical waterway is reopened, Reuters reported.

The Iranian official, who had issued the demands on behalf of the Islamic Republic, has been replaced by the country's supreme leader with a veteran Revolutionary Guards commander who has previously voiced skepticism about talks with the US, CNN reported.

The front-month US West Texas Intermediate crude oil contract jumped 4.2% to $81.49 a barrel, and global benchmark North Sea Brent advanced 4.3% to $87.09 a barrel.

US Treasury yields rose, with the 10-year yield up 4.3 basis points to 4.7% and the two-year higher by 3.7 basis points to 4.24%.

Gold futures rose 0.4% to $4,416.9, and silver futures jumped 2.8% to $65.27.

In company news, Trade Desk (TTD) slid 5.5%, one of the worst performers on the S&P 500, following stock rating downgrades from multiple brokerages, including DA Davidson.

Apple (AAPL) has enabled eligible Mac users in mainland China to connect Alibaba's (BABA) Qwen artificial intelligence service to Siri and Writing Tools, Reuters reported Friday. The arrangement gives Apple a locally developed AI option for Mac users in China, the report said. Jefferies downgraded Apple to underperform from hold while adjusting its price target to $263.66 from $285.56.

Shares of Apple dropped 2%, one of the worst performers on the Dow.