Renesas Electronics Corp. said Monday the Japanese semiconductor maker expects output capacity at a plant damaged by a blaze last month to return to pre-fire levels in May, as some production has resumed amid concern about a further worsening of the global chip shortage.

Renesas, the major supplier of semiconductors for auto use, resumed some operations at the plant in Ibaraki Prefecture near Tokyo on Saturday with output capacity at around 10 percent of what it used to be before the March 19 fire. It is aiming to raise that level to 30 percent this week and then 50 percent by the end of April.

Supplied photo taken on April 9, 2021, shows a clean room at Renesas Electronics Corp.'s Naka plant in Ibaraki Prefecture. (Kyodo)

For shipments to recover fully, Renesas has said it will take about 100 days, or three months from the fire. Renesas President and CEO Hidetoshi Shibata said there could be a "slight delay" of around seven to 10 days regarding the time frame.

"There remains a lot of work to be done to restore operations inside the factory...so we aim to make sure output will return to what it used to be as soon as possible," Shibata told a press briefing.

Shibata called the 100-day time frame "ambitious," but the fact it has been able to resume some output at the factory in just one month is a "miracle." He expressed his appreciation to the company's suppliers for sending their employees and providing "incredible support" to put back the facility online.

Renesas President and CEO Hidetoshi Shibata gives an online press conference on April 19, 2021, as seen in this screenshot image. (Kyodo)

The manufacturing of semiconductors involves multiple stages and takes about a month to complete before shipment.

It was feared the March fire could exacerbate the global shortage in chips, which are used in everything from laptops, smartphones, and game consoles to cars, and the production of which has been greatly affected by the pandemic.

The shortage has already affected automakers such as Mitsubishi Motors Corp. and Subaru Corp., which have decided to reduce output irrespective of the fire at Renesas.

The blaze at the Renesas plant, apparently caused by an electricity overload, burned around 600 square meters and damaged a total of 23 machines in the factory.

Shibata said the assistance Renesas has received from other companies reflected their "efforts to prevent (the shortage of) semiconductors from affecting economic growth."

The Japanese government, for its part, is exploring ways to secure a stable supply of chips. At a summit meeting on Friday, Japanese Prime Minister Yoshihide Suga and U.S. President Joe Biden agreed to step up bilateral cooperation over sensitive semiconductor supply chains and critical technologies such as 5G.