* Kellogg up after strong results
* Under Armour slumps after results; drags down Nike
* FOMC to start two-day policy meeting
* Indexes up: Dow 0.03 pct, S&P 0.10 pct, Nasdaq 0.23 pct (Updates to open)
Oct 31 (Reuters) - A rise in technology stocks and strong earnings from Oreo cookie maker Mondelez buoyed the S&P and the Nasdaq on Tuesday, while a decline in Pfizer weighed on the Dow.
Mondelez jumped nearly 6.23 percent after the company reported better-than-expected profit and revenue on cost cuts and higher demand in Europe and Latin America.
A 7.76 percent surge in Kellogg's shares following a surprise rise in quarterly sales helped the S&P consumer staples index gain 0.48 percent.
"We're still in the thick of earnings and have seen some high-profile companies driving the market a lot," said Randy Frederick, vice president of trading and derivatives for Charles Schwab in Austin, Texas.
The earnings season is being closely tracked to justify stretched valuations and results have been largely above expectations.
With more than half the S&P 500 components reported, third-quarter earnings are estimated to have climbed 6.7 percent, up from an expectation of 5.9-percent growth at the start of October, according to Thomson Reuters I/B/E/S.
The Federal Open Market Committee starts its two-day meeting in Washington to discuss interest rates amid an impending announcement on the next Fed chair.
President Donald Trump is likely to pick Fed Governor Jerome Powell as the next head of the U.S. central bank on Thursday. U.S. Treasury yields fell after the report on Monday as Powell is seen as more dovish than other contenders.
The central bank is likely to refrain from raising rates after the meeting, with economists expecting a hike only in December, according to a Reuters poll.
"The bigger news as far as economics goes is the payroll numbers on Friday."
At 9:37 a.m. ET (1337 GMT), the Dow Jones Industrial Average was up 6.18 points, or 0.03 percent, at 23,354.92, the S&P 500 was up 2.57 points, or 0.10 percent, at 2,575.4 and the Nasdaq Composite was up 15.40 points, or 0.23 percent, at 6,714.36.
Pfizer shares fell 1.3 percent despite the drugmaker's profit beat and upbeat forecast.
Under Armour slumped 14.75 percent after the company slashed 2017 sales and profit forecasts and reported its first year-on-year fall in revenue. Bigger rival and Dow component Nike declined about 1 percent.
Qualcomm dipped 6.35 percent after Reuters reported that Apple has designed iPhones and iPads that would drop chips supplied by Qualcomm.
Advancing issues outnumbered decliners on the NYSE by 1,649 to 900. On the Nasdaq, 1,605 issues rose and 721 fell. (Reporting by Sruthi Shankar; Editing by Sriraj Kalluvila)