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* Facebook drops after brokerage downgrade
* Nike falls after boycott gains traction on social media
* Deadline for U.S.-China tariff consultations on Thursday
* Amazon touches $1 trillion in market cap
* Indexes down: Dow 0.05 pct, S&P 0.17 pct, Nasdaq 0.23 pct (Updates to close)
By April Joyner
NEW YORK, Sept 4 (Reuters) - U.S. stocks fell on Tuesday as trade concerns lingered and declines in Facebook and Nike shares weighed on Wall Street's major indexes, though data showing U.S. manufacturing activity accelerated in August kept losses in check.
Facebook Inc shares fell 2.6 percent after brokerage MoffettNathanson downgraded the social media company, warning of revenue growth deceleration.
Shares of other technology companies, including Alphabet , Microsoft Corp and Twitter Inc also slid, while the S&P 500 technology index dropped 0.3 percent.
Nike Inc shares fell 3.2 percent as the company faced a backlash after it chose Colin Kaepernick, the first NFL player to kneel during the national anthem as a protest against racism, to participate in a new ad campaign.
Concerns about trade, including talks between the United States and Canada to renegotiate the North American Free Trade Agreement, also took a toll, investors said.
"The trade war concerns continue to linger," said Stephen Massocca, senior vice president at Wedbush Securities in San Francisco. "The fact that we weren't able to come to an agreement with Canada has people concerned."
Talks between the United States and Canada are scheduled to resume on Wednesday after the two parties ended their talks on Friday without a deal.
Amazon Inc bucked the negative sentiment. It briefly touched $1 trillion in market capitalization, joining Apple Inc in achieving that milestone, after its shares rose as much as 1.9 percent to hit a record $2,050.50. Amazon ended the session up 1.3 percent to $2,039.51.
The Dow Jones Industrial Average fell 12.34 points, or 0.05 percent, to 25,952.48, the S&P 500 lost 4.8 points, or 0.17 percent, to 2,896.72 and the Nasdaq Composite dropped 18.29 points, or 0.23 percent, to 8,091.25.
Earlier, the indexes pared losses after data from the Institute for Supply Management showed U.S. manufacturing activity accelerated to a more than 14-year high in August, boosted by a surge in new orders.
Consultations on a U.S. proposal for new tariffs on Chinese goods are set to end on Thursday, after which U.S. President Donald Trump can follow through on plans to impose levies on another $200 billion of Chinese imports, though it is unclear how quickly that will happen.
Verizon Communications Inc shares slipped 2.2 percent after Barclays downgraded the wireless carrier's stock.
Shares of Western Digital Corp fell 4.7 percent and Seagate Technology PLC shares dropped 7.7 percent after Evercore ISI downgraded shares of the hard-disk drive makers.
Shares of JD.com Inc slid 6.0 percent after the Chinese retailer's chief executive officer was arrested in the United States on suspicion of criminal sexual conduct and later released.
Declining issues outnumbered advancing ones on the NYSE by a 1.90-to-1 ratio; on Nasdaq, a 1.42-to-1 ratio favored decliners.
The S&P 500 posted 53 new 52-week highs and eight new lows; the Nasdaq Composite recorded 153 new highs and 50 new lows.
Volume on U.S. exchanges was 6.56 billion shares, compared to the 6.11 billion average over the last 20 trading days. (Reporting by April Joyner in New York; Additional reporting by Shreyashi Sanyal in Bengaluru; Editing by Susan Thomas and Leslie Adler)