Dec 29 (Reuters) - Australian shares jumped on Wednesday to their highest in more than three and a half months as market participants grew less concerned about the Omicron coronavirus variant on returning from an extended holiday weekend. By 0012 GMT, the S&P/ASX 200 index (.AXJO) had risen 1% to 7,496, their highest since Sept. 9, driven by gains in banks and miners. Financial markets in Australia and New Zealand were closed on Monday and Tuesday for the Christmas and Boxing Day holidays. The S&P/ASX 200 index, which had risen nearly 13% this year by last close, was set for a fifth straight session of gains, even as Australia recorded another record surge in COVID-19 infections on Tuesday. read more Heavyweight financials (.AXFJ) rose as much as 1.6% to their highest since Nov. 17, with the so-called "Big Four" banks up between 1% and 1.7%. Commonwealth bank of Australia (CBA.AX) advanced as much as 1.6% to its highest since Nov. 17, while Westpac Banking Corp (WBC.AX) jumped 1.7% to its highest in more than a month. Miners (.AXMM) rose as much as 1% to their highest in nearly four months, with Pilbara Minerals (PLS.AX) and Perenti Global (PRN.AX) jumping 5.1% and 6.7%, respectively. Energy stocks (.AXEJ) rose 1.1% after crude oil prices settled higher overnight, supported by supply outages and expectations that U.S. inventories fell last week. Major oil and gas explorer Santos (STO.AX) added 1.5%, while Woodside Petroleum (WPL.AX) rose as much as 2.2% to its highest in nearly two weeks. Healthcare stocks (.AXHJ) jumped as much as 1.2% and were set for their sixth straight session of gains. On Wall Street, the S&P 500 (.SPX) closed slightly lower after hitting a record intraday high on Tuesday, as a four-day rally lost steam and investors weighed Omicron-driven travel disruptions and store closures. New Zealand"s benchmark S&P/NZX 50 index (.NZ50) rose 0.8% to a six-week high of 12,995.63.