REFILE-US STOCKS-Wall Street dips, ends 3-day rally ahead of quarter's end, U.S. presidential debate

(adds dropped word in first paragraph)
* First U.S. presidential debate due to start at 9 p.m. EDT
* Democratic sweep modestly positive for S&P 500 profits -
GS
* Consumer confidence surges in September
* Indexes down: Dow 0.36%, S&P 500 0.32%, Nasdaq 0.09%

By Stephen Culp
NEW YORK, Sept 29 (Reuters) - Wall Street dipped on Tuesday,
snapping a three-day winning streak as investors took money off
the table ahead of the end of the quarter and hours before the
first presidential debate.
All three major U.S. stock indexes were down. In a reversal
from Monday, market leaders Apple Inc AAPL.O , Microsoft Corp
MSFT.O and Amazon.com AMZN.O weighed heaviest on the S&P 500
and the Nasdaq.
"It's profit-taking after several solid back-to-back
rallies," said Peter Cardillo, chief market economist at Spartan
Capital Securities in New York. "It's end-of-the-quarter
portfolio window dressing."
"I don't think it's anxiety over the debate," Cardillo
added.
Market participants eyed the first head-to-head showdown
between President Donald Trump and Democratic challenger Joe
Biden in a debate expected to air from Cleveland Tuesday
evening. "Whoever tonight's winner might be will have no effect on
the markets," Cardillo said. "The market has to a degree
discounted a Democratic victory and it will be business as
usual."
The latest poll shows Biden leading nationally and in a
number of key battleground states. While a win by either candidate has implications for
different sectors, notably healthcare, green energy and
beneficiaries of Trump's corporate tax cuts, Goldman Sachs
analysts expected a Democratic sweep of the White House and both
chambers of Congress would be beneficial to S&P 500 profits
through 2024. In the closing days of September and the second quarter, the
major indexes are on track to post their first monthly declines
since March, when the mandated shutdowns brought the economy to
a grinding halt.
But despite September's expected loss, the S&P and the
Nasdaq are on course for their best two-quarter winning streaks
since 2009 and 2000, respectively.
U.S. House of Representatives Speaker Nancy Pelosi unveiled
a new, $2.2 trillion coronavirus relief bill proposed by House
Democrats, a sign of potential progress in the partisan
tug-of-war over the new aid package nearly two months after
emergency unemployment benefits expired for millions.
The proposed package gave airlines some hope for a second
bailout, just days before tens of thousands of layoffs are
expected to occur. Still, the S&P 1500 Airline index .SPCOMAIR was down 2.8%.
Stocks were given a brief boost early in the session by data
from the Conference Board, which showed consumer confidence
surging past expectations this month with the largest point gain
in 17 years.
The Dow Jones Industrial Average .DJI fell 99.88 points,
or 0.36%, to 27,484.18, the S&P 500 .SPX lost 10.65 points, or
0.32%, to 3,340.95 and the Nasdaq Composite .IXIC dropped 9.55
points, or 0.09%, to 11,107.98.
Of the 11 major sectors in the S&P 500, energy .SPNY and
financials .SPSY suffered the largest percentage losses.
Sorrento Therapeutics SRNE.O jumped 12.1% after the
company's COVID-19 antibody candidates showed promise in a
study. Fitbit Inc FIT.N advanced 6.3% after Reuters reported
Alphabet Inc GOOGL.O was poised to win EU approval for its
$2.1 billion acquisition of the fitness tracker maker.
Declining issues outnumbered advancing ones on the NYSE by a
1.72-to-1 ratio; on Nasdaq, a 1.23-to-1 ratio favored decliners.
The S&P 500 posted 6 new 52-week highs and no new lows; the
Nasdaq Composite recorded 59 new highs and 31 new lows.