* Apple at session highs after falling 4.2 pct post results
* Biogen's strong profit beat lifts shares
* Mondelez gives biggest boost to Nasdaq
* Dow up 0.27 pct, S&P down 0.05 pct, Nasdaq down 0.32 pct (Updates to early afternoon)
By Yashaswini Swamynathan
Oct 26 (Reuters) - A rally in Boeing's shares helped the Dow reverse course in the early afternoon session on Wednesday, while Apple continued to weigh on the Nasdaq and the S&P 500.
Apple's shares fell 2.6 percent after the world's most valuable public company said sales of its flagship iPhones fell for the third quarter in a row.
Apple was the top drag on all three major indexes. The S&P 500 technology index fell 0.25 percent, weighing the most on the benchmark index.
Boeing shares were trading at their highest level this year, after the world's largest planemaker reported a jump in quarterly profit despite slower sales. The stock gave the biggest boost to the S&P and the Dow.
Movement on Wall Street has largely been dictated by corporate earnings in the past few weeks, but events such as the Nov. 8 U.S. presidential election and the Federal Reserve's policy meet next week have added volatility.
Overall earnings of S&P 500 companies are expected to rise 2.2 percent, snapping a four-quarter streak of profit declines, according to Thomson Reuters I/B/E/S.
Excluding Apple, earnings are expected to grow at a 2.9 percent rate.
"The markets have been rallying in anticipation of good numbers and earnings have been coming in a little bit soft," said Paul Nolte, portfolio manager at Kingsview Asset Management in Chicago.
The CBOE Market Volatility index was up for the second day in a row, after having been in negative territory for the past five trading days.
"While earnings in the technology sector haven't been fabulous, you are going to have better performance in general out of the sector, because revenue is still growing and they have great cash flow," Nolte said.
At 12:36 a.m. ET (1636 GMT), the Dow Jones Industrial Average was up 48.93 points, or 0.27 percent, at 18,218.2.
The S&P 500 was down 1.04 points, or 0.05 percent, at 2,142.12 and the Nasdaq Composite was down 16.97 points, or 0.32 percent, at 5,266.43.
One bright spot on the Nasdaq was Mondelez, which is on track for its best day in nearly two months after reporting a third-quarter profit that beat estimates.
Chipotle Mexican Grill was on track for its worst day this year, with its shares off 8.2 percent after the restaurant chain operator reported a bigger-than-expected drop in quarterly sales at established restaurants.
Edwards Lifesciences was the biggest loser on the S&P 500, falling 13.6 percent after the medical device maker reported third-quarter sales that missed expectations.
Declining issues outnumbered advancing ones on the NYSE by 1,678 to 1,156. On the Nasdaq, 1,482 issues fell and 1,168 advanced.
The S&P showed nine new 52-week highs and five new lows, while the Nasdaq recorded 44 new highs and 56 new lows. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Don Sebastian)