TOKYO- Japan's crude steel output dropped 19.3% in September from a year earlier, falling for the seventh month in a row as the COVID-19 pandemic continued to weigh on demand, the Japan Iron and Steel Federation said on Thursday.

Output, which is not seasonally-adjusted, declined to 6.49 million tonnes in the world's No.3 steel producer, but it increased 0.6% from August, marking a third straight month-to-month rise.

"Demand remained weak due to the coronavirus pandemic, but output gradually increased from the previous month as industry activities, especially in automobile sector, picked up," a researcher at the federation said.

Japan's top two steelmakers, Nippon Steel Corp and JFE Steel, owned by JFE Holdings Inc, temporarily shut several blast furnaces in April-July as a result of dwindling demand.

But JFE Steel restarted a blast furnace in Fukuyama, western Japan, in mid-September to meet recovering demand.

Nippon Steel also plans to restart a blast furnace in Kimitsu, eastern Japan, in November. 

For the July-September quarter, Japan's crude steel output fell 22.7% on the year to 18.98 million tonnes.

Output plunged 26.8% to 37.10 million tonnes for the April-September half year.

(Reporting by Yuka Obayashi; Editing by Mark Potter) ((Yuka.Obayashi@thomsonreuters.com; +813-4563-2761;))