BANGKOK—Major world share benchmarks were mixed at the outset of the last trading week of the year as countries grappled with the spread of the omicron coronavirus variant. Benchmarks were flat early Monday in Paris and Frankfurt and fell in Shanghai, Bangkok, Tokyo, and Seoul. Taiwan and India were higher. London and some other markets were closed for holidays. Comments by China’s central bank, over the weekend about support for the slowing economy highlighted differences in stances among countries trying to balance support for economic recoveries from the pandemic with measures to keep inflation in check. The Federal Reserve is among a handful of central banks that have already begun cutting interest rates or otherwise cutting back on the extra support they provided when the pandemic first slammed world economies in early 2020. “The divergences in global monetary policy are set for a sharper turn heading into the new year, …