(Company corrects number of factories affected to 14 (not 15), paragraph 3) Aug 19 (Reuters) - Toyota Motor Corp will slash global production for September by 40% from its previous plan, the company said on Thursday, becoming the last major automaker to cut output due to critical shortages of semiconductors. The world’s largest automaker by sales volumes has fared better than rivals, having built a larger stockpile of chips under a business continuity plan adopted after the 2011 earthquake and the Fukushima nuclear disaster. But a resurgence in COVID-19 cases across Asia has compounded the semiconductor crunch. A Toyota executive said the September cuts included 14 factories in Japan and overseas plants, and that it was reducing its planned global production that month by around 360,000 vehicles. Toyota shares closed down 4.4% in their biggest daily drop since December 2018, pulling the benchmark Nikkei average to a seven-month low. Toyota said this month it was facing an unpredictable business environment due to fresh COVID-19 cases in emerging economies, the semiconductor shortage and soaring material prices. The carmaker had already halted assembly lines at some Japanese factories between late July and early August, including its Tahara plant, due to a surge in infections in Vietnam which had constrained the supply of parts, the Nikkei reported earlier. A person familiar with the matter told Reuters this month that Toyota had also suspended production at one assembly line in Guangzhou, China, which it operates with its Chinese joint-venture partner Guangzhou Automobile Group Co Ltd . In Thailand too, Toyota suspended production last month at three factories due to a pandemic-related parts shortage. (Reporting by Jahnavi Nidumolu in Bengaluru, Maki Shiraki and Ritsuko Ando in Tokyo; Writing by Sayantani Ghosh; Editing by Edwina Gibbs and Tomasz Janowski) Our Standards: The Thomson Reuters Trust Principles.