In 2.47pm trading, the Standard & Poor's 500 Index rose 0.5 per cent. The S&P 500 climbed to a record 2,417.72 while the Nasdaq touched a record 6,217.34.
The Dow advanced as gains in shares of UnitedHealth and those of Microsoft, up 1.8 per cent and 1.5 per cent higher respectively, outweighed slides in shares of Chevron and those of DuPont, recently each down 1.3 per cent.
Minutes from the Federal Reserve's May meeting, released on Wednesday, kept alive bets that policy makers will raise interest rates next month.
"While markets may be thinking June is a done deal, some on the Fed appear to be less certain," Michael Hewson, a market analyst at CMC Markets in London, wrote in a note, Bloomberg reported.
Meanwhile, a Labour Department report showed that initial claims for state unemployment benefits increased 1,000 to a seasonally adjusted 234,000 for the week ended May 20. The increase was less than economists had predicted.
Oil prices dropped below US$50 after the Organisation of the Petroleum Exporting Countries and other non-OPEC members agreed to prolong a reduction in oil supplies by nine months, as had been widely expected. Still, some had hoped for more. "Members participating in the output deal failing to agree on deeper cuts have given a bearish signal to the market as an extension alone may not rebalance the market fast enough," Abhishek Kumar, senior energy analyst at Interfax Energy's Global Gas Analytics in London, told Reuters.
West Texas Intermediate for July delivery dropped US$2.46 to settle at US$48.90 a barrel on the New York Mercantile Exchange, according to Bloomberg.
In Europe, the Stoxx 600 Index edged less than 0.1 per cent lower from the previous close. France's CAC40 Index slipped 0.1 per cent, while Germany's DAX Index fell 0.2 per cent. The UK's FTSE 100 Index eked out a 0.04 per cent gain.