Investors stripped nearly a fifth off the value of Pioneer Corp. on Wednesday, the day after the troubled Japanese electronics company warned it is heading for a fifth straight year of heavy losses as it wrestles with costly restructuring at its ailing TV operations.

Pioneer’s shares skidded 18 percent to close at 909 yen ($8.63) in Tokyo, valuing the company at 191 billion yen ($1.81 billion), while the Nikkei index of Tokyo’s blue chips ended the day down 0.1 percent.

At their current level, shares in Pioneer are above their all-time low of 722 yen ($6.86) hit in January.

The company said Tuesday its net loss in the fiscal year which ended March 31 widened to 17.99 billion yen ($170.8 million) from 6.76 billion yen _ its fourth straight year in the red. The company also predicted a 36 percent drop in the current fiscal year’s operating profit, which shows how its core businesses are doing.

Pioneer said it expects 15 billion yen ($142.5 million) in “structural reform” costs to lead to a net loss of 19 billion yen ($180.5 million) this fiscal year.

Credit Suisse analyst Koya Tabata said in a report that the operating profit forecast was worse than expected, and underlines the company’s predictions that its home electronics business will take a while to recover.

Pioneer said Tuesday it will close two of its three plasma display panel plants in Japan to cut costs as it begins to buy the panels from Matsushita Electric Industrial Co. The third plant will focus on assembly, it said.