* Ukraine conflict continues, Russia seizes marine base
* Weak China data raises hopes for stimulus
* Nasdaq hit as trading favorites like Netflix, Tesla sink
* Herbalife rallies, Icahn to get more reps on board
* Dow flat, S&P 500 down 0.3 pct, Nasdaq down 0.9 pct (Updates to open, adds Markit data)
By Ryan Vlastelica
NEW YORK, March 24 (Reuters) - U.S. stocks fell on Monday as the ongoing crisis in Ukraine weighed on sentiment and pushed investors to take profits in some of the market's biggest trading favorites.
Futures had been higher throughout the premarket session, lifted by hopes that China would take stimulative measures to support its economy, but indexes turned lower early, with the Nasdaq especially hit hard as Netflix and Tesla tumbled.
Losses were limited in the Dow by a rise in Procter & Gamble Co, a consumer staple that is considered a defensive play. That stock rose 2 percent to $79.42, snapping a four-day losing streak.
Ukraine announced the evacuation of its troops from Crimea, essentially yielding the region to Russian forces, which earlier seized a Ukrainian marine base there. While few U.S. companies have excessive exposure to the region, investors are concerned about the potential economic fallout from any escalation in tensions.
U.S. President Barack Obama, who has imposed personal sanctions against some of Russian President Vladimir Putin's political and business allies, began crisis talks with his European allies over how to respond in the biggest East-West conflict since the Cold War.
"The issue remains contained for the time being, but Obama will try and garner support for more sanctions, which will ultimately shape our view of how things can end up looking," said Art Hogan, chief market strategist at Wunderlich Securities in New York. "This remains at the forefront of what we're paying attention to."
China's manufacturing engine contracted in the first quarter of 2014, according to the flash Markit/HSBC Purchasing Managers' Index. The report came in below expectations but raised hopes for new stimulative measures.
"Any hint that China will finally move in the direction of stimulus will be a positive for the economy, especially since data from other regions hasn't been so weak that it changes the view of the economy continuing to grow," Hogan said.
The Dow Jones industrial average was up 2.92 points, or 0.02 percent, at 16,305.69. The Standard & Poor's 500 Index was down 5.95 points, or 0.32 percent, at 1,860.57. The Nasdaq Composite Index was down 37.41 points, or 0.87 percent, at 4,239.38.
The Nasdaq was pressured by steep losses in some of its biggest recent outperformers. Netflix Inc dropped 4.9 percent to $386.09 while Tesla Motors shed 3.5 percent to $220 and Facebook Inc slid 2.5 percent to $65.59.
Netflix was the S&P's biggest percentage gainer in 2013, while Tesla soared 344 percent last year and extended that rally by more than 40 percent so far this year.
"Once stocks like these stumble, they fall really hard," said Kim Forrest, senior equity research analyst, Fort Pitt Capital Group in Pittsburgh. "Everyone loves them on the way up, but no one does on the way down."
In the latest economic data, financial data firm Markit said its preliminary read on March U.S. manufacturing activity slowed after nearing a four-year high last month, but the rate of growth and the pace of hiring remained strong.
Herbalife Ltd said it would allow three more representatives of billionaire investor Carl Icahn, the company's biggest shareholder, to join its board. Shares of the nutrition and weight-loss company jumped 4.8 percent to $51.94.
NU Skin Enterprises Inc shares soared about 19.1 percent to $89.34 on heavy volume. Earlier, China fined the company more than $500,000 for illegal product sales and misleading local consumers, China's State Administration for Industry & Commerce said in a statement on its website. NU Skin last week said it expected a fine.
The Wall Street Journal reported that Apple Inc was in talks with Comcast Corp to enter a deal for a streaming-television service that would allow Apple set-top boxes to bypass congestion on the web. The companies declined to comment on the report. Shares of Apple rose 1.3 percent to $539.85 while Comcast dipped 0.5 percent to $49.72.
Nokia Corp said it doesn't expect to close the sale of its phone business to Microsoft until April as talks with Asian regulators drag on, fuelling speculation it may have to make more concessions to get the deal done. U.S. shares of Nokia rose 1.4 percent to $7.27. (Editing by Bernadette Baum and Nick Zieminski)