The French carmaker said it would take the charge after changing the way it accounts for its shares in the Japanese carmaker.

French carmaker Renault will report an extraordinary loss of about 9.5 billion euros ($11 billion) on its stake in Nissan Motor in the first half, it said on Tuesday, writing down its years-long investment in the Japanese firm that is battling slumping sales.

Renault reported an $11 billion non-cash loss on its 35.7% Nissan stake, shifting to a share price-based accounting method. Nissan's weak sales, outdated lineup, and $4.5 billion loss highlight the strained alliance.