* All 3 major U.S. stock averages essentially flat
* Fed cuts interest rates as expected
* Treasury yields slide, yield curve flattens (Updates to afternoon with Fed rate decision)
By Stephen Culp
NEW YORK, Oct 30 (Reuters) - Wall Street pared earlier losses and the U.S. Treasury yield curve flattened on Wednesday after the Federal Reserve cut interest rates, as expected.
At the conclusion of its two-day monetary policy meeting, the Fed cut key interest rates for the third time this year, as it eyes uncertainties stemming from the protracted trade war and assesses the strength of the longest-ever period of economic expansion in U.S. history.
Earlier in the session, a spate of mixed corporate earnings and a decline in the U.S. GDP growth rate kept investors cautious. Market participants will scrutinize Fed Chair Jerome Powell's remarks later in the session for clues regarding the way ahead for the central bank's economic policy.
The Commerce Department's advance reading of third-quarter GDP showed the U.S. economy expanded at a 1.9% annual rate, down from 2% in the second quarter but beating the 1.6% growth rate analysts expected.
"The market's not doing much right now. It's trying to assess what the Fed said," said Robert Pavlik, chief investment strategist, senior portfolio manager at SlateStone Wealth LLC in New York. "It's left the markets in a bit of a black hole as it doesn't know what the next move will be."
Investors now look to Fed Chair Powell's statement expected shortly.
"(Powell will be) trying to thread a needle and he has to be careful as to how he answers the questions," Pavlik added. "It'll be fairly muted."
The Dow Jones Industrial Average rose 7.98 points, or 0.03%, to 27,079.4, the S&P 500 lost 2.62 points, or 0.09%, to 3,034.27 and the Nasdaq Composite dropped 9.14 points, or 0.11%, to 8,267.71.
European shares inched lower on bank earnings and doubts over an interim U.S.-China trade deal.
The pan-European STOXX 600 index rose 0.08% and MSCI's gauge of stocks across the globe shed 0.10%.
Emerging market stocks lost 0.38%. MSCI's broadest index of Asia-Pacific shares outside Japan closed 0.3% lower, while Japan's Nikkei lost 0.57%.
The U.S. Treasury yield curve flattened following the Fed's announcement.
Benchmark 10-year notes last rose 7/32 in price to yield 1.8103%, from 1.835% late Tuesday.
The 30-year bond last rose 30/32 in price to yield 2.287%, from 2.331% late Tuesday.
The dollar was nominally higher against a basket of major world currencies.
The dollar index rose 0.04%, with the euro up 0.03% to $1.1113.
The Japanese yen weakened 0.10% versus the greenback at 109.00 per dollar, while Sterling was last trading at $1.2882, up 0.13% on the day.
Oil prices fell on worries about a possible delay in resolving the U.S.-China trade war, which has hurt global oil demand.
U.S. crude fell 0.79% to $55.10 per barrel and Brent was last at $60.31, down 1.5% on the day.
Gold prices edged lower, reversing earlier gains.
Spot gold dropped 0.1% to $1,486.52 an ounce.
Copper lost 0.72% to $5,885.00 a tonne.
Reporting by Stephen Culp Editing by Chris Reese