TOKYO, Sept 9 (Reuters) - Japan’s Nikkei index retreated from a near six-month high to close lower on Thursday, in line with global markets as worries flared about slowing economic growth due to the fast-spreading Delta coronavirus variant. The Nikkei share average closed down 0.57% at 30,008.19, snapping an eight-day winning streak — the longest since early-November. The broader Topix fell 0.71% to 2,064.93, down from a three-decade closing high of 2,079.61 on Wednesday. “Following the extended winning streak, it’s natural there will be some selling, but there’s a sense that the view that stocks have further to rise, is providing a firm base,” said a market participant at a domestic securities firm. An index of Asia-Pacific shares excluding Japan fell 1.32% as the Tokyo Stock Exchange ended the trading day. The Federal Reserve’s Beige Book showed a “downshift” in the U.S. economy last month due to the spread of COVID-19. Meanwhile, Japan’s government said it plans to extend COVID-19 emergency restrictions in Tokyo and other regions. SoftBank Group was the biggest drag on the Nikkei, sliding 1.93%. The stock had surged on Wednesday after a $7 billion share-swap deal with Deutsche Telekom. Uniqlo chain operator Fast Retailing was the second-biggest drag, declining 0.65%. Air transport was the worst performing subsector on the Topix, dropping 1.74%. Japan Airlines sank 1.62% after sources said it is looking to raise 300 billion yen to ride out anticipated funding challenges. Rival ANA Holdings slid 1.84%. The electric and gas subsector, however, was the outperformer, rising 3.2%. Potential contender for Japan’s prime ministership Taro Kono, a well-known critic of nuclear energy, moderated his tone somewhat, saying he would tolerate atomic power for the time being. Tokyo Electric Power Company Holdings was the biggest gainer on the Nikkei, rallying 11.03%, followed by a 5.36% gain for Kansai Electic Power Co. (Reporting by Tokyo markets team; Editing by Ramakrishnan M. and Uttaresh.V)