* Nikkei +0.6% before extended Olympics weekend * U.S. yields, dollar edge higher; gold down SHANGHAI, July 21 (Reuters) - Asian shares stumbled on Wednesday, giving up early gains, while the dollar was firm as investors worried that a fast-spreading coronavirus variant could impede a global economic recovery. But European share markets were set for a slightly higher open following sharp falls early in the week, ahead of a European Central Bank meeting on Thursday that is expected to convey a dovish tone. Euro Stoxx 50 futures rose 0.16% and German DAX futures were up 0.07%. FTSE futures added 0.08%. The Delta coronavirus variant has for the moment displaced inflation as investors’ primary source of concern, with South Korea on Wednesday reporting a daily record of new infections. ADVERTISEMENT Last week, data showing a surge in U.S. consumer prices in June had sparked fears that the Federal Reserve could bring a quicker end to emergency stimulus measures. The shift from a debate over whether price spikes are transitory to outright fear of the impact of the latest COVID-19 surge has pushed the U.S. 10-year yield down more than 20 basis points in the space of a week as investors have moved into safe haven assets. The S&P 500 slumped nearly 4% from highs last Wednesday to lows on Monday before rebounding. On Wednesday, MSCI’s broadest index of Asia-Pacific shares outside Japan reversed early gains to slip 0.14%, extending losses for the week to more than 2%. Seoul’s KOSPI slid 0.29% and Hong Kong’s Hang Seng index fell 0.46%. Japan’s Nikkei was 0.6% higher after touching six-month lows a day earlier, as investors bought cyclical stocks ahead of a long weekend that will mark the start of the Tokyo 2020 Olympics and as a jump in exports in June boosted hopes for an export-led economic recovery. Chinese blue-chip shares were also higher, up 0.81% “The level of volumes, the level of sporadic whip-saw price action I think is telling you that there’s not a lot of conviction one way or another,” said Kay Van-Petersen, global macro strategist at Saxo Capital Markets in Singapore. But while he said peak global growth had likely passed, easy central bank policies continue to provide strong support for global asset prices even as they begin to flag the tapering of asset purchases. “The G4 central banks’ balance sheets have been compounding by 15% since 2008. And my point is that’s not going to stop. It’s not going to get shut off.” U.S. Treasuries prices edged down, with the 10-year yield rising to 1.2151% from the previous day’s close of 1.209%. The 2-year yield was at 0.2037%, up from a close of 0.194%. But echoing concern in equities markets over a surge in global COVID-19 infections, the dollar stayed near three-month highs on Wednesday. “While some of the world is shrugging off rising infections as vaccination rates limit the severity of any symptoms of new cases, there are few parts of the world that can totally ignore this,” said Rob Carnell, Asia-Pacific chief economist at ING. The dollar index was last up 0.08% at 93.041, with the euro down 0.07% to $1.1771. The dollar was 0.05% stronger against the yen at 109.89. Oil prices resumed their decline after a rebound on Tuesday, as an industry report showed an unexpected build-up in U.S. oil inventories. U.S. West Texas Intermediate crude dropped 0.46% to $66.89 per barrel and Brent traded at $69.06 per barrel, down 0.42% on the day. Spot gold shed 0.07% to $1,808.84 an ounce as U.S. yields rebounded. Reporting by Andrew Galbraith; Editing by Christopher Cushing and Kim Coghill