* Emerging markets stumble, lead global stocks down
* U.S.-Canada talks, China tariffs deadline loom
* MSCI world stock index down for fourth day in a row (New throughout, updates prices, market activity and comments to late afternoon)
By Sinéad Carew
NEW YORK, Sept 5 (Reuters) - Emerging market stocks lead declines in indexes across the globe on Wednesday as investors looked to take risk off the table while a deadline in the U.S.-China trade conflict loomed and U.S.-Canada trade talks resumed.
Weakness in emerging market currencies helped support the dollar, which retreated modestly as the euro rose and Britain's sterling regained some ground in volatile trading after a four-day losing streak.
The United States and Canada resumed talks about revamping the North American Free Trade Agreement (NAFTA). Canada insisted there was room to salvage the pact despite few signs a deal was close. U.S. President Donald Trump said the United States should have a fair trade deal with Canada.
A public comment period on the possibility of fresh U.S. tariffs on another $200 billion of Chinese goods ends on Thursday, with expectations that Trump will impose the additional levies.
The deadline weighed on MSCI's emerging markets equities index, which fell 1.7 percent in line with a drop in the Shanghai SE Composite index.
"The linchpin will be China," said Sameer Samana, global equity and technical strategist for Wells Fargo Investment Institute, in St. Louis, adding that if China continues to grow, other emerging market countries could regain ground.
"We're actually kicking the tires to see where there's value," Samana said.
The Dow Jones Industrial Average rose 7.4 points, or 0.03 percent, to 25,959.88, the S&P 500 lost 7.71 points, or 0.27 percent, to 2,889.01 and the Nasdaq Composite dropped 93.60 points, or 1.16 percent, to 7,997.65.
The pan-European FTSEurofirst 300 index lost 1.20 percent and MSCI's gauge of stocks across the globe shed 0.60 percent.
Emerging market currencies showed a second day of declines, with a JPMorgan emerging market currency index falling 0.2 percent on fears export-oriented economies would be caught in the crossfire of any escalating trade conflict.
Sterling was last trading at $1.2906, up 0.40 percent on the day as investors positioned for a favorable Brexit outcome even after Germany appeared to shoot down an earlier report that Berlin and London might abandon key Brexit demands.
Measured against a basket of currencies, the dollar index fell 0.31 percent, with the euro up 0.41 percent to $1.1628.
Treasuries Benchmark 10-year notes last fell 1/32 in price to yield 2.904 percent, from 2.902 percent late on Tuesday. The 30-year bond last fell 5/32 in price to yield 3.077 percent, from 3.069 percent late on Tuesday.
Oil prices fell after a U.S. Gulf storm weakened and moved away from oil-producing areas, and on mounting concerns about global trade disputes and Turkey's currency crisis hurting demand.
U.S. crude fell 1.47 percent to $68.84 per barrel and Brent was last at $77.28, down 1.14 percent on the day.
Additional reporting by Saqib Iqbal Ahmed in New York, Shreyashi Sanyal in Bengaluru, Sujata Rao in London, Shinichi Saoshiro in Tokyo; Editing by Bernadette Baum and David Gregorio