Sony, which reported a record $5.7 billion annual loss Thursday, dived 6.43 percent to 1,135 yen, while Panasonic closed down 1.55 percent at 570 yen shortly before posting a record $9.67 billion annual loss on Friday.
The firms’ shares stood at their lowest level since at least 1980, taking into account previous stock splits, according to the online edition of the Nikkei business daily.
Meanwhile shares in Sharp, which has posted a record $4.7 billion annual net loss, also ended at their lowest level in decades, down 5.10 percent to 390 yen.
The sell-off came after Sony said it lost 456.66 billion yen ($5.7 billion) in the year to March, its fourth consecutive year in the red, but vowed to swing back to profitability this year.
Sony has struggled to stem losses at its television division and counted a strong yen and natural disasters among the reasons for its disastrous results.
Shortly after the closing bell Friday, Panasonic confirmed earlier warnings of a record loss, among the worst-ever shortfalls recorded by a non-financial Japanese company.
Falling unit prices, particularly in the television segment, have eaten away at the bottom line of major Japanese electronics makers as a strong yen made their products pricier overseas while a stuttering global economy knocked sales.
Sony, along with Panasonic and Sharp, has been fighting a losing battle for years against fierce competition offered from the likes of South Korea’s Samsung and US-based Apple.
Analysts have called on Sony to drastically overhaul its business, including possibly leaving the TV business all together.
Last month, Sony said it would cut about 10,000 jobs and spend nearly $1 billion on an overhaul that its new chief executive Kazuo Hirai described as “urgent”.
“On the whole, (Sony) remains at risk of ongoing losses in its cellular application and TV businesses, and we continue to see little prospect of a rise in valuations for the time being,” Credit Suisse analysts Yuan Tian and Shunsuke Tsuchiya said in a client note.