* Mondelez, Kellogg gain after strong results
* All three indexes on track to record monthly gains
* Under Armour slumps after results
* FOMC to start two-day policy meeting
* Indexes up: Dow 0.12 pct, S&P 0.13 pct, Nasdaq 0.30 pct (Updates to early afternoon)
Oct 31 (Reuters) - Gains in technology stocks and a jump in shares of consumer companies Mondelez and Kellogg on Tuesday put the three major Wall Street indexes on track for their best monthly gains since February.
Apple rose 1.4 percent to a record high after positive reviews of its much-anticipated iPhone X. The stock provided the biggest boost to all the three major indexes.
Intel hit a 17-year high following a report that Apple has designed iPhones and iPads that would drop chips supplied by Qualcomm. Qualcomm plunged 7.3 percent and was the biggest drag on the S&P and the Nasdaq.
Strong earnings from Mondelez and Kellogg helped the S&P consumer staples index gain 0.85 percent.
Mondelez jumped 5.73 percent after the Oreo cookie maker reported better-than-expected profit and revenue, while Kellogg surged 6 percent following its first sales increase in more than two years.
"Earnings have been the key driver," said Jeff Carbone, managing partner at Cornerstone Financial Partners. "We're going through a period without any major pullbacks and that must be warranted to the economic data and earnings."
Third-quarter earnings are being closely tracked to justify stretched valuations in stocks and the results so far have been largely above expectations.
With more than half the S&P 500 components reported, earnings are estimated to have climbed 7 percent in the quarter, up from an expectation of a 5.9-percent growth at the start of October, according to Thomson Reuters I/B/E/S.
Investors are also waiting for an announcement on the next Federal Reserve chair. President Donald Trump is likely to pick Fed Governor Jerome Powell, who is seen as more dovish, as the next head, sources have told Reuters.
The Federal Open Market Committee starts its two-day meeting in Washington on Tuesday to discuss interest rates where it is widely expected to leave rates unchanged.
At 12:25 p.m. ET (1625 GMT), the Dow Jones Industrial Average was up 27.68 points, or 0.12 percent, at 23,376.42, the S&P 500 was up 3.41 points, or 0.13 percent, at 2,576.24 and the Nasdaq Composite was up 20.10 points, or 0.3 percent, at 6,719.06.
Nine of the 11 major S&P indexes were higher, with losses only in healthcare and real estate sectors.
"I wouldn't be surprised to see some rotational changes as we're over the worst period," said Carbone.
Pfizer fell 1 percent after results.
Under Armour Inc slumped about 18 percent after the company slashed 2017 forecasts and reported its first quarterly fall in revenue since going public.
Advancing issues outnumbered decliners on the NYSE by 1,737 to 1,090. On the Nasdaq, 1,788 issues rose and 1,028 fell.
(Reporting by Sruthi Shankar; Editing by Sriraj Kalluvila)