(Updates with volume, after-hours stock moves)
* Netflix and Philip Morris rally after results
* Etsy, Virtu shares surge in IPOs
* Apple weighs on market
* Dow finishes down 0.04 pct, S&P 500 down 0.08 pct Nasdaq loses 0.06 pct
By Noel Randewich
April 16 (Reuters) - U.S. stocks ended marginally lower on Thursday as lingering worries about upcoming corporate earnings reports offset enthusiasm about a trio of soaring Wall Street debuts.
Weighing on the S&P 500 were Apple and General Electric, which is expected to report its first-quarter results on Friday before the start of trading.
The S&P 500's top gainer, Netflix, closed 18.21 percent higher a day after the video streaming service posted better-than-expected results.
Shares of Etsy Inc, an online marketplace for handmade goods and crafts, finished 87.5 percent higher and private-equity backed Party City's stock jumped 21.77 percent in their IPOs.
The stock of electronic trading firm Virtu Financial Inc closed 16.74 percent higher in its market debut in a sign that public angst over high-frequency trading is waning.
The Dow Jones industrial average fell 6.84 points, or 0.04 percent, to end at 18,105.77. The S&P 500 lost 1.64 points, or 0.08 percent, to 2,104.99 and the Nasdaq Composite dropped 3.23 points, or 0.06 percent, to 5,007.79.
Of the 51 companies in the S&P 500 that have reported so far, 76.5 percent exceeded profit expectations, well above the long-term average of 63 percent.
After mixed trading sessions this week, major indexes are about 1 percent below record highs despite recent concerns about weakness in first-quarter earnings. But it is too early to pronounce the March-quarter earnings season an unexpected success, strategists said.
"Where are we on earnings? We know they're going to be negative year over year but just how negative are they going to be?" said Jim Bianco, president of Bianco Research in Chicago.
"It's a game. The analysts will cut too far so the companies can beat."
Apple closed 0.48 percent lower at $126.17 while GE ended down 0.65 percent at $27.28, with analysts on average expecting the conglomerate to post a dip in quarterly earnings, according to Thomson Reuters data.
First-quarter earnings for S&P 500 companies are expected to have declined 2.6 percent from a year ago, according to Thomson Reuters data, hurt by low oil prices, a strong dollar and extreme weather in the eastern United States. Revenue is forecast down 2.8 percent from a year ago.
SanDisk lost 4.51 percent to close at $67.91 after its forecast. Philip Morris International's stock surged 8.74 percent to $84.96 after the cigarette maker's profit fell less than expected in the first quarter.
After the bell, Mattel Inc posted quarterly results that sent its shares 7.7 percent higher. American Express fell 1 percent after its quarterly report.
On Thursday, declining issues outnumbered advancing ones on the NYSE by 1,700 to 1,333, for a 1.28-to-1 ratio on the downside; on the Nasdaq, 1,434 issues fell and 1,289 advanced, for a 1.11-to-1 ratio.
The S&P 500 posted 8 new 52-week highs and no new lows; the Nasdaq Composite recorded 102 new highs and 17 new lows.
About 6.3 billion shares changed hands on U.S. exchanges, compared with the 6.2 billion daily average for the month to date, according to data from BATS Global Markets. (Additional reporting by Ryan Vlastelica and Caroline Valetkevitch; Editing by Bernadette Baum, Nick Zieminski and Meredith Mazzilli)