* Fed chair says U.S. economy still needs help
* Mondelez climbs after earnings, coffee deal
* Internet-related shares drop for second day
* Whole Foods tumbles after earnings, outlook
* Dow up 0.6 pct; S&P 500 up 0.2 pct; Nasdaq off 1.1 pct (Updates to early afternoon)
By Chuck Mikolajczak
NEW YORK, May 7 (Reuters) - U.S. stocks mostly rose on Wednesday, bouncing off earlier lows after comments from Federal Reserve Chair Janet Yellen offered no surprises, but the Nasdaq fell for a second straight day, weighed down by declines in Internet-related shares.
The Dow and the S&P 500 moved into positive territory after Yellen said the U.S. economy was still in need of lots of support, given the "considerable slack" in the labor market in remarks to the congressional Joint Economic Committee.
Yellen's comments enabled investors to shift attention to what may be an easing of the tensions in Ukraine, as Russian President Vladimir Putin called on pro-Moscow separatists in Ukraine to postpone a vote on secession just five days before it was to be held.
But the Nasdaq remained under pressure as stocks such as Amazon.com Inc, down 2.6 percent at $289.55; Facebook Inc, down 2.8 percent at $56.91; and Google Inc , down 1.6 percent at $514.31, all weighed heavily on the index. The Nasdaq has dropped more than 2 percent over the past two sessions.
"Janet Yellen didn't say anything new in her testimony. She continues to talk about how they are data dependent, how they can change on a dime, but she didn't say rates are going up any time soon, which is exactly what people expected," said Ken Polcari, director of the NYSE floor division at O'Neil Securities in New York.
"Coupled with the fact that technically the market found some support, then (investors) started concentrating on what Putin said," Polcari added.
The Dow Jones industrial average rose 92.48 points or 0.56 percent, to 16,493.50. The S&P 500 gained 3.53 points or 0.19 percent, to 1,871.25. The Nasdaq Composite dropped 42.892 points or 1.05 percent, to 4,037.867.
Whole Foods Market Inc also contributed to the Nasdaq's decline as the organic grocer's stock tumbled 19 percent to $38.82. The stock was the biggest drag on both the S&P 500 and Nasdaq 100 indexes a day after Whole Foods posted second-quarter results and cut its 2014 outlook. Rivals such as Sprouts Farmers Market, down 13.7 percent at $26.83, and The Fresh Market, down 8.9 percent at $32.64, also slumped.
Of 422 companies in the S&P 500 that had reported earnings through Wednesday morning, 68.2 percent beat expectations, above the 63 percent average since 1994, and exceeding the 66 percent beat rate for the past four quarters, according to Thomson Reuters data.
Profits are expected to rise 5 percent this quarter, down from 6.5 percent estimated at the start of the year, but above the low of 0.6 percent in mid-April, according to Thomson Reuters data.
Shares of Mondelez International Inc jumped 7.4 percent to $37.83 and gave the biggest boost to the S&P 500 after the company posted first-quarter earnings and said it reached a deal with Dutch coffee and tea company D.E Master Blenders 1753 BV.
Electronic Arts shares surged 16.8 percent to $32.75 after the video game publisher posted quarterly profit and revenue that beat expectations.
In the latest snapshot of the U.S. economy, the Labor Department said that U.S. nonfarm productivity fell at its fastest pace in a year in the first quarter because of severe weather. That led to the largest gain in unit labor costs in more than a year. Productivity fell at a 1.7 percent annual rate in the quarter, the Labor Department said. (Editing by Bernadette Baum and Jan Paschal)