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* Wells Fargo rises on new CEO appointment
* Micron falls on weak Q1 profit outlook
* Indexes down: Dow 0.6%, S&P 1%, Nasdaq 1.7% (Updates to late afternoon)
By Ambar Warrick and Medha Singh
NEW YORK, Sept 27 (Reuters) - U.S. stocks fell on Friday after news that the Trump administration was considering delisting Chinese companies from U.S. stock exchanges and limit U.S. investments into China.
The tariff-sensitive Philadelphia semiconductor index extended its decline to 2.7%. The index was already under pressure from Micron Technology Inc's tumble after it forecast a disappointing first-quarter profit.
The S&P technology sector dropped 1.8%. U.S.-listed shares of Alibaba Group Holding Ltd, Baidu Inc and JD.com Inc were sharply lower.
High-level trade talks between Washington and Beijing are scheduled for next month before the start of the third-quarter earnings season.
"If our policies spark a major sell off in Shanghai where that creates problems for China that could negatively impact the trade negotiations which are supposed to start on Oct. 10. That is where the U.S. based fear would come from," said Michael O'Rourke, chief market strategist at JonesTrading in Greenwich, Connecticut.
Adding to the negative momentum, the S&P 500 index fell below its 50-day moving average in afternoon trading.
At 2:55PM ET, the Dow Jones Industrial Average fell 162.36 points, or 0.6%, to 26,728.76, the S&P 500 lost 30.49 points, or 1.02%, to 2,947.13 and the Nasdaq Composite dropped 136.58 points, or 1.7%, to 7,894.08.
The three main indexes are set to end lower in a volatile week, which included U.S. Democrats launching an impeachment investigation on President Donald Trump.
Shares of Wells Fargo & Co rose 3.6% and the stock was among top gainers on the S&P 500 after the lender named banking veteran Charles Scharf as chief executive officer.
Data earlier showed U.S. consumer spending barely rose in August, suggesting that the economy's main growth engine was slowing after accelerating sharply in the second quarter.
Declining issues outnumbered advancing ones on the NYSE by a 1.77-to-1 ratio; on Nasdaq, a 2.05-to-1 ratio favored decliners.
The S&P 500 posted 11 new 52-week highs and 6 new lows; the Nasdaq Composite recorded 26 new highs and 104 new lows. (Additional reporting by Ambar Warrick and Medha Singh in Bengaluru; Editing by Shounak Dasgupta and Chizu Nomiyama)