* Whole Foods tumbles after earnings, outlook
* Internet-related shares drop for second day
* Yellen congressional testimony due
* Indexes: Dow up 0.08 pct, S&P down 0.06 pct, Nasdaq off 1.02 pct (Updates to open, adds quote, Yellen remarks)
By Chuck Mikolajczak
NEW YORK, May 7 (Reuters) - U.S. stocks were little changed on Wednesday, but the Nasdaq slid for a second day, dragged lower by weakness in Internet shares.
Stocks such as Amazon.com Inc, down 1.9 percent at $291.50, Facebook Inc, down 2.3 percent at $57.17 and Google Inc, down 1.5 percent at $514.88, all weighed heavily on the Nasdaq, which has shed more than 2 percent over the past two sessions.
"Nasdaq continues to be the underperformer of the group and more air comes out of that momentum trade," said Peter Kenny, chief executive of Clearpool Group in New York.
"It is also providing for a degree of doubt to seep into the market that seems to be resonating with each passing day; in other words, the sense the market's inevitable move is higher is being re-examined the more people focus on Nasdaq. It's having a real impact on market psychology."
Remarks by Federal Reserve Chair Janet Yellen failed to boost equities. In testimony to the congressional Joint Economic Committee, Yellen said the central bank would continue to provide a high degree of monetary policy accommodation, and cited geo-political turmoil and weak housing data as risks to the U.S. economy.
Whole Foods Market Inc contributed to the decline as it tumbled 19.8 percent to $38.47 as the biggest drag on both the S&P 500 and Nasdaq 100 NDX> indexes after the organic grocer posted second-quarter results and cut its 2014 outlook.
The Dow Jones industrial average rose 13 points, or 0.08 percent, to 16,414.02, the S&P 500 lost 1.13 points, or 0.06 percent, to 1,866.59 and the Nasdaq Composite dropped 41.753 points, or 1.02 percent, to 4,039.006.
According to Thomson Reuters data through Wednesday morning, of 422 companies in the S&P 500 that have reported earnings, 68.2 percent beat expectations, above the 63 percent average since 1994 and 66 percent beat rate for the past four quarters.
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.
U.S. nonfarm productivity fell at its fastest pace in a year in the first quarter due to severe weather, leading 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.
Mondelez International Inc was a bright spot, as shares jumped 7.7 percent to $37.92 after it posted first-quarter earnings and said it reached a deal with Dutch coffee and tea company D.E Master Blenders 1753 BV.
Electronic Arts also moved higher, as shares surged 15.5 percent to $32.40 after the video game publisher posted quarterly profit and revenue that beat expectations. (Editing by Bernadette Baum)