The shocking arrest of its former Chairman Carlos Ghosn last November has brought a series of headaches to Nissan Motor Co., such as conducting an internal investigation into that matter and reforming its weak corporate governance.

But the earnings report and forecast disclosed Tuesday by the Yokohama-based automaker underscored a bigger problem — stabilizing its auto business.

Nissan's operating profit for the fiscal year ended in March plunged by 44.6 percent to ¥318 billion ($2.9 billion) from the previous year. The figure is projected to decrease further to ¥230 billion for the current year, which will be the lowest in 11 years.