Volkswagen , Northvolt's top shareholder, has significantly written down its 21% stake in the Swedish battery cells maker that filed for bankruptcy protection in the United States last week, two people familiar with the matter said.

Volkswagen bet big on European-made batteries a few years ago with two massive investments in Northvolt, the Swedish manufacturer. Now the automaker’s €1.4 billion stake is worth less than half that, according to Reuters. The write-downs occurred throughout the current fiscal year as the situation at Northvolt deteriorated.

Volkswagen (OTCPK:VWAGY) has taken a major writedown of its 21% stake in the Swedish battery company, Northvolt, Reuters reported Monday, citing two sources. The writedowns at the German automobile giant were done throughout the current financial year,