(For a live blog on the U.S. stock market, click or type LIVE/ in a news window.)
* China to halve extra tariffs on some U.S. imports
* Twitter advances as quarterly revenue tops $1 bln
* Kellogg declines after earnings outlook disappoints
* Indexes: Dow flat, S&P up 0.15%, Nasdaq up 0.29% (Updates to open)
By Medha Singh
Feb 6 (Reuters) - The S&P 500 and Dow Jones Industrials indexes eased from their record highs on Thursday, as investors took a breather after a stellar run this week on waning worries about the economic damage from the coronavirus epidemic.
Both indexes scaled new levels at the open as China said it would halve extra tariffs on some U.S. goods following hefty stimulus to support an economy hit by shutdowns and travel restrictions due to the virus outbreak.
"The fear investors had when the virus first started seems to have abated somewhat," said Rick Meckler, partner, Cherry Lane Investments, a family investment office in New Vernon, New Jersey.
A string of positive U.S. economic data have also helped mitigate worries, fueling a Wall Street rally this week. The Nasdaq hit a record high in the previous session and the benchmark S&P 500 is on pace for its best week in eight months.
However, the impact of the health emergency in China continued to show up in corporate reports. Chipmaker Qualcomm Inc flagged a potential threat to the mobile phone industry from the outbreak. Its shares fell 4%.
At 10:18 a.m. ET, the Dow Jones Industrial Average was nearly unchanged at 29,287.91, while the S&P 500 was up 4.86 points, or 0.15%, at 3,339.55. The Nasdaq Composite was up 27.17 points, or 0.29%, at 9,535.86.
Seven of the 11 major indexes were lower, led by a 0.8% fall for energy stocks.
Breakfast cereal maker Kellogg Co tumbled 6.1% after it forecast full-year earnings well below market expectations.
Becton, Dickinson and Co dropped 11.2% after the medical technology company lowered its full-year revenue and profit forecasts. The stock was the biggest drag on the S&P 500.
Philip Morris International Inc gained 4.4% after the Marlboro cigarettes maker topped quarterly profit estimates.
Twitter Inc gained about 15.5% after the micro-blogging platform touched $1 billion in quarterly revenue for the first time ever, beating analysts' estimates.
Advancing issues outnumbered decliners by a 1.20-to-1 ratio on the NYSE and by a 1.16-to-1 ratio on the Nasdaq.
The S&P index recorded 55 new 52-week highs and no new low, while the Nasdaq recorded 81 new highs and 20 new lows.
As the week draws to a close, investor attention will shift to the crucial U.S. jobs report on Friday. (Reporting by Medha Singh in Bengaluru Editing by Arun Koyyur and Saumyadeb Chakrabarty)