* Graphic: World FX rates in 2018 tmsnrt.rs/2egbfVh
* Trump OKs $50B in tariffs as China vows retaliation
* World stocks suffer as euro rebounds against dollar
* Oil down 3 pct on prospect for higher output
By Nick Brown
NEW YORK, June 15 (Reuters) - World shares fell on Friday after U.S. President Donald Trump announced new tariffs that sparked fears of a trade war between the U.S. and China, while oil prices plummeted 3 percent over signs that supply may soon rise.
Trump announced hefty tariffs on $50 billion of Chinese imports on Friday, with Beijing threatening to respond in kind, in a move that could ignite a trade war between the world's two biggest economies.
Trump unveiled a 25 percent tariff on a list of strategically important imports from China, promising further measures if Beijing struck back.
MSCI's gauge of stocks across the globe shed 0.59 percent, while the pan-European FTSEurofirst 300 index lost 0.76 percent.
Emerging market stocks were hit particularly hard, tumbling 1.20 percent, a move maybe attributable as much to a strong dollar as to trade tensions.
"I think the biggest concern at the moment, more than talk about trade, is the tightening of monetary conditions in emerging markets caused by a stronger dollar," said Michael Hewson, chief markets analyst at CMC Markets in London, noting the Federal Reserve's forecast for a total of four interest rate rises in 2018.
Trump's decision on tariffs comes a day after stock markets had rallied on the European Central Bank's decision to hold off on raising rates at least until the middle of next year.
U.S. share indexes were feeling the hit from the impending tariffs in morning trading.
The Dow Jones Industrial Average fell 206.32 points, or 0.82 percent, to 24,968.99, the S&P 500 lost 10.85 points, or 0.39 percent, to 2,771.64 and the Nasdaq Composite dropped 27.06 points, or 0.35 percent, to 7,733.98.
The outbreak of a global trade war has been the most frequently cited 'biggest tail risk' by investors this year in Bank of America Merrill Lynch's monthly survey of global fund managers, on the back of ramped up protectionist rhetoric and measures by the U.S. administration.
It is not clear when Trump will activate the measures, but rising Sino-U.S. tensions will put more pressure on China's economy, which is starting to show signs of cooling.
MSCI's broadest index of Asia-Pacific shares outside Japan closed 0.65 percent lower, with Chinese stocks leading the losses.
World oil markets cratered in early trading on fears of increased supply, with U.S. crude down 2.8 percent to $65.02 per barrel and Brent last at $73.55, down 3.15 percent.
The Organization of Petroleum Exporting Countries is slated to meet next week in Vienna, with two of the biggest producers - Saudi Arabia and Russia - indicating they were prepared to increase output.
"Everyone is talking about raising production - the only question is by how much," said Bob Yawger, director, energy at Mizuho in New York.
In currencies, the U.S. dollar slipped against the safe-haven yen in the wake of the announced tariffs, while the dollar index, which measures the greenback against six top currencies, fell 0.04 percent.
The euro, which on Thursday had suffered its biggest fall against the dollar in two years after the ECB's interest rate decision, jumped 0.41 percent to $1.1615.
Trade fears drove demand for safe government bonds, causing U.S. treasury yields to fall to their lowest levels in a week. Benchmark 10-year notes last rose 11/32 in price to yield 2.9059 percent, from 2.946 percent late on Thursday.
The 30-year bond rose 24/32 in price to yield 3.0284 percent, from 3.066 percent Thursday.
“You’ve seen a little bit of a risk-off trade, which is aiding in the Treasury rally,” said Justin Lederer, an interest rate strategist at Cantor Fitzgerald in New York.
Additional reporting by Ritvik Carvalho, Jessica Resnick-Ault and Karen Brettell; Editing by Bernadette Baum