* Comments from Fed's Clarida spark talk of rate-hike end
* Trump trade talk helps S&P 500 end positive
* Pound, euro rebound amid Brexit uncertainty
* Oil prices post sixth straight week of losses (Updates with close of U.S. trading)
By Lewis Krauskopf
NEW YORK, Nov 16 (Reuters) - The U.S. dollar weakened and Treasury yields slid on Friday after a top Federal Reserve official said U.S. interest rates were near a neutral rate, while the S&P 500 ended positive after a seesaw session helped by optimism over U.S.-China trade ties.
Oil prices steadied but still posted their sixth straight week of losses. Uncertainty over Britain's exit from the European Union clouded currency and other markets.
Markets were shaken by comments made by Richard Clarida, newly appointed Fed vice chair, in a CNBC interview that U.S. interest rates were nearing Fed estimates of a neutral rate, and being at neutral "makes sense."
He also said there was "some evidence of global slowing."
While the Fed is widely expected to raise rates in December, the number of hikes next year is a matter of debate.
"The big driver right now is Fed speech," said Guy LeBas, chief fixed income strategist at Janney Montgomery Scott in Philadelphia. "Clarida indicated a modestly dovish bent on Fed policy, and not a particularly aggressive stance."
On Wall Street, the Dow Jones Industrial Average rose 123.95 points, or 0.49 percent, to 25,413.22, the S&P 500 gained 5.94 points, or 0.22 percent, to 2,736.14 and the Nasdaq Composite dropped 11.16 points, or 0.15 percent, to 7,247.87.
Clarida's comments helped support stocks, which were also boosted by comments from President Donald Trump on trade.
Trump said he may not impose more tariffs on Chinese goods after Beijing sent the United States a list of measures it was willing to take to resolve trade tensions.
"The market is paying attention very closely to anything surrounding trade," said Veronica Willis, investment strategy analyst at Wells Fargo Investment Institute in St. Louis. "(A trade deal) would boost expectations for global growth, which would ultimately be good for stocks."
Investors are pointing toward the G20 meeting later this month, when leaders from the United States and China are expected to meet, and the Fed's meeting in December as key events for markets.
Weighing on equity sentiment and the Nasdaq was a disappointing forecast by chip company Nvidia Corp. Nvidia shares tumbled 18.8 percent while the Philadelphia semiconductor index fell 1.2 percent.
MSCI's gauge of stocks across the globe gained 0.35 percent.
The pan-European STOXX 600 index lost 0.20 percent as traders waited on more clarity involving Britain's exit from the EU, known as Brexit.
British Prime Minister Theresa May won the backing of the most prominent Brexiteer in her government as she fought to save a draft EU divorce deal that has stirred up a plot to force her out of her job.
After tumbling a day earlier, sterling was last trading at $1.2825, up 0.40 percent, while the euro was up 0.78 percent to $1.1414.
"Sterling volatility has woken up from its 100-year slumber and is likely to remain reactive," said Ulrich Leuchtmannan, FX strategist at Commerzbank.
The dollar index, which measures the greenback against a basket of currencies, fell 0.49 percent.
Benchmark 10-year notes last rose 12/32 in price to yield 3.0738 percent, from 3.118 percent late on Thursday.
U.S. crude settled unchanged at $56.46 a barrel, and Brent settled at $66.76 a barrel, up 0.21 percent.
Additional reporting by Richard Leong, April Joyner and Gertrude Chavez-Dreyfuss in New York, Tom Finn and Tommy Wilkes in London; Editing by Phil Berlowitz, Bernadette Baum and Sonya Hepinstall