TOKYO, Jan 14 (Reuters) - Japan"s Nikkei index touched a near four-week low on Friday, tracking weak overnight performance on Wall Street, with technology heavyweights leading the losses, while concerns over the impact of the Omicron variant also curbed risk appetite. The Nikkei share average (.N225) was down 1.9% at 27,937.76, as of 0200 GMT, after falling below 28,000 for the first time since Dec. 20. The broader Topix (.TOPX) dropped 2.06% to 1,964.21. The Nikkei lost about 2% so far this week and Topix slipped 1.6% for the week. "The Japanese market fell too much today - it dropped more than the Dow and S&P overnight. Sentiment has been weakened by the expected rate hikes in the United States so there are not many buyers for Japanese shares," said Jun Morita, general manager of the research department at Chibagin Asset Management. All major indexes on Wall Street closed lower, with the tech-heavy Nasdaq leading losses after a three-day rally, amid talks signalling that the U.S. Federal Reserve would raise rates as early as in March. "Investors are also worried about the Omicron impact. Japan was faring better than other countries, but now the number of infections have started surging here as well." Tokyo recorded a new four-month high in COVID-19 infections on Thursday, and experts forecast the spread of the Omicron will cause the daily count to triple by month"s end. read more Staffing agency Recruit Holdings (6098.T), which many investors see as a tech stock due to its holding in U.S. online job search firm Indeed, dragged down the Nikkei the most with a 5.52% drop. Robot maker Fanuc (6954.T) fell 4.81% and air-conditioner maker Daikin Industries (6367.T) slipped 4.07%. Fast Retailing (9983.T) jumped 7.17%, as the owner of Uniqlo clothing stores said it would have to raise pries of some products due to higher costs for raw materials and shipping. read more Hitachi gave up early gains to fall 1.21% after local media reported the conglomerate would sell part of its stake in Hitachi Construction Machinery . read more Hitachi Construction tumbled 17.52%.