* Euro jumps as investors bet on ECB stimulus wind-down
* U.S. Treasury prices extend gains
* U.S. stocks mixed (Updates with oil price settlements)
By Caroline Valetkevitch
NEW YORK, June 7 (Reuters) - The euro climbed to a three-week peak on Thursday as expectations mounted that the European Central Bank will signal an early wind-down of economic stimulus, while oil prices jumped on concern about a drop in Venezuela exports.
U.S. Treasury prices extended gains as worries about global trade and losses in emerging markets sparked a fresh wave of safe-haven demand for U.S. government debt.
The ECB, at its policy meeting next week, will debate whether to end bond purchases later this year, its chief economist, Peter Praet, a close ally of ECB President Mario Draghi, said on Wednesday. Other ECB officials echoed Praet's sentiment.
The comments drove the euro as high as $1.1840, the highest level since May 17. The European single currency has risen for four straight sessions. Since hitting a 10-month low last week, it has gained nearly 3 percent.
The euro was last up 0.22 percent to $1.1799. The dollar index, which tracks the greenback against a basket of major currencies, fell 0.24 percent.
"Any signal next week that the bank plans to go ahead with winding down its asset purchases in the fall could add to the euro’s broadly improved tone," said Omer Esiner, chief market analyst at Commonwealth Foreign Exchange in Washington.
Oil prices received a boost from worries over a steep drop in exports from crisis-plagued Venezuela, which faces the threat of U.S. sanctions.
U.S. crude rose $1.22 to settle at $65.95 a barrel, while Brent gained $1.96 to settle at $77.32.
The higher prices helped energy shares on Wall Street, with the S&P 500 energy index last up 1.7 percent, making it the biggest percentage gainer among sectors.
U.S. stock indexes were mixed, as a rally in tech stocks ended and set up the Nasdaq for its first loss in five days, while a 4.4 percent jump in McDonald's shares following news of potential layoffs boosted the Dow.
The Dow Jones Industrial Average rose 87.19 points, or 0.35 percent, to 25,233.58, the S&P 500 lost 2.83 points, or 0.10 percent, to 2,769.52, and the Nasdaq Composite dropped 54.46 points, or 0.71 percent, to 7,634.78.
The pan-European FTSEurofirst 300 index lost 0.19 percent and MSCI's gauge of stocks across the globe shed 0.03 percent.
Emerging market stocks lost 0.30 percent.
Investors were focused on the upcoming G7 summit of seven major economies, amid a widening divide over trade between U.S. President Donald Trump and the group's remaining six members after Trump imposed tariffs on steel and aluminum imports from Canada, Mexico and the European Union last week.
The summit takes place on Friday and Saturday in Charlevoix, Quebec.
The global trade worries boosted Treasury prices.
Benchmark 10-year notes last rose 15/32 in price to yield 2.9204 percent, from 2.975 percent late on Wednesday.
In the metals markets, copper hit a 4-1/2-year high, lifted by concerns over the potential that wage negotiations at the world's biggest copper mine could disrupt supply.
Copper rose 0.37 percent to $7,247.00 a tonne.