U.S. stock-index benchmarks opened solidly higher Friday, with the Dow industrials attempting to snap a eight-day skid, amid rising tensions over global trade between the U.S. and its partners in China and Europe. An agreement between members of the Organization of the Petroleum Exporting Countries and other oil producers to lift an output curb also was in focus. The Dow Jones Industrial Average rose 150 points, or 0.6%, at 24,608, the S&P 500 index climbed 0.5% to 2,762. The Nasdaq Composite Index advanced 0.2% at 7,725. All three benchmarks are on track for weekly declines, on the back of intensifying worries on trade. The Dow is set for a 1.9% weekly drop, the S&P 500 is on track to shed 0.6% for the 5-session period, while the Nasdaq is set for a 0.3% slide over the same period. The European Union said it would begin implementing tariffs on $3.2 billion in U.S. imports on Friday. That comes after President Donald Trump threatened to impose some $400 billion in tariffs on China earlier in the week. In the crude market, U.S. benchmark oil was up 3.3% after OPEC ministers tentatively agreed Friday to a deal to join other big producers in adding around 600,000 barrels a day of oil to global markets, according to people familiar with the matter. That was less than the 1 million barrel raise that was expected, supporting gains in crude. In stocks, shares of Red Hat Inc. fell after the software company offered a weaker-than-expected quarterly outlook.