The shutdown, initially announced on 23 March, was to have ended on 17 April, but will now be extended at least until 8 May, Inside Indiana Business reported.
Production is now scheduled to resume three days later on 11 May, the report said.
The shutdown will continue because of declining market demand and supply chain issues caused by the ongoing COVID-19 pandemic, the report added. The production facility employs some 6,000 people.
Subaru paid hourly workers full wages for the first three weeks of the shutdown, but a full furlough became effective this week. Hourly employees are still receiving their health insurance and related benefits, according to the news outlet.