NEW YORK (REUTERS) - The Dow Jones Industrial Average briefly broke above the 23,000-point mark for the first time on Tuesday (Oct 17), driven by strong earnings from UnitedHealth and Johnson & Johnson, but finished the session just below that milestone.

The blue-chip index, which surpassed similar 1,000-point marks three times previously this year, has been steadily inching higher and is up 2.6 percent so far this month, putting it on track for a seventh straight monthly advance.

Still, the Dow may in the near term have a difficult time sustaining a move above 23,000, said Robert Pavlik, chief market strategist at Boston Private Wealth in New York.

"My view is it may pull back before staying above" that level.

"It may take several days or a couple of weeks," he said.

"Right now, you're contending with earnings season and the fact that the market has run up leading up into the earnings season," Pavlik said.

Shares of the largest US health insurer UnitedHealth touched a life intraday high and closed up 5.5 per cent after the company reported a stronger-than-expected profit and raised its full-year earnings forecast.

Johnson & Johnson, up 3.4 per cent, also posted better-than-expected results and raised its forecast, leading a 1.3 per cent gain in the S&P health-care sector.

The Dow Jones Industrial Average rose 40.48 points, or 0.18 per cent, to end at 22,997.44 after rising as high as 23,002.20.

The S&P 500 gained 1.72 points, or 0.07 per cent, to 2,559.36. and the Nasdaq Composite dropped 0.35 point, or 0.01 per cent, to 6,623.66.

Also boosting some health insurers and US hospital operators was news of a bipartisan deal in the US Senate to stabilise Obamacare. Shares of Anthem were up 1.9 per cent, while shares of Tenet Healthcare were up 5.3 per cent.

Financials were the biggest drag on the S&P 500, with shares of Goldman Sachs down 2.6 per cent despite reporting a profit beat and smaller-than-expected trading revenue fall.

Netflix slipped 1.6 per cent after touching a record high as more subscribers signed up for its original content in the latest quarter.

Declining issues outnumbered advancing ones on the NYSE by a 1.37-to-1 ratio; on Nasdaq, a 1.72-to-1 ratio favoured decliners.

About 5.5 billion shares changed hands on US exchanges. That compares with the 5.9 billion daily average for the past 20 trading days, according to Thomson Reuters data.