HONG KONG, Aug 26 (Reuters) - Asian shares retreated on Thursday, brushing off an upbeat Wall Street lead as the Delta coronavirus variant"s spread darkened the regional mood while a South Korean interest rate hike put the focus on the global central bank outlook. Investors are mostly waiting for the Federal Reserve"s Jackson Hole symposium on Friday and what central bank chair Jerome Powell might say about U.S. tapering monetary stimulus. MSCI"s broadest index of Asia-Pacific shares outside Japan (.MIAPJ0000PUS) dropped 0.60%, and U.S. stock futures the S&P 500 e-minis , shed 0.14%. Chinese bluechips (.CSI300) fell 1.47% and Hong Kong (.HSI) was down 1.32%, as a rally in tech names ran out of steam. The embattled Hang Seng Tech Index fell 2.41%. A profit warning from Evergrande (3333.HK), China"s most indebted property developer sent its shares down 7.24%. Elsewhere, the Australian benchmark (.AXJO) lost 0.7% as the country"s new daily cases of COVID-19 topped 1,000 for the first time. Japan"s Nikkei (.N225) was little changed having spent the day flickering either side of flat. The Asian stock benchmark is still up around 3.5% on the week, having largely joined a global rally as investors look to the Fed"s upcoming Jackson Hole symposium for assurances the central bank won"t be rushing to tighten policy. However, Asia is lagging the rest of the world this year. The MSCI world equity index (.MIWD00000PUS), which tracks shares in 50 countries, is sitting very close to record highs, while the MSCI Asia ex-Japan benchmark is off over 12% from its record highs hit in February. Overnight, U.S. shares inched higher with the S&P 500 (.SPX) closing at its 51st record high of the year, gaining 0.22%. "Asia would be doing a lot better if it were not for the Delta outbreak. However, we"ve seen at various times over the last 18 months where different regions have led and lagged depending on where they are in relation to COVID -19," said Shane Oliver, Chief Economist at AMP. South Korea on Thursday reported a jump in the number of critical or severe cases while infections hit records in Vietnam and the Philippines this week. POLICY CHANGES The global inflationary pulse was also in the headlines as the South Korean central bank lifted its base rate off a record low, the first major economy in Asia to do so. read more Governor Lee Ju-yeol maintained his hawkish tone and suggested the bank could further tighten policy as data showed Asia"s fourth-largest economy was overheating. Central banks around the world are laying the groundwork for a transition away from crisis-era stimulus as what began as emergency support for collapsing growth now overheats many economies. Investors and policymakers are particularly focused on what the Fed"s Powell signals at Jackson Hole on Friday. "Ideally, the Fed would like to observe as long as possible, (and)...make sure that the economy is well on track towards growth," Raghuram Rajan, former RBI governor and finance professor at the University of Chicago Booth School of Business, told the Reuters Global Markets Forum on Wednesday. "Of course, the problem is the Delta variant, plus whatever variants are lurking in the background." Treasury yields rose in U.S. hours though inched down again in Asia. The yield on benchmark 10-year Treasury notes was 1.3356% compared with its U.S. close of 1.344% on Wednesday. The dollar was little changed sitting around a week-low against a basket of major peers , amid the more positive U.S. mood. Oil prices fell on Thursday after three days of gains. U.S. crude dipped 0.80% to $67.96 a barrel. Brent crude fell 0.57% to $71.93 per barrel.