Nissan Motor Co.'s independent board members met Tuesday to discuss who should succeed Carlos Ghosn as chairman. Their choice to replace the ousted car titan, now languishing in Tokyo Detention House, will indicate the direction the automaker's alliance with Renault SA will take.

The most likely successors fall on each end of the spectrum: President and Chief Executive Officer Hiroto Saikawa, who has emerged as a driving force behind the investigation into Ghosn's financial reporting, and Toshiyuki Shiga, a former Ghosn confidant, according to sources familiar with the situation.

The external directors have already said they will choose an existing board member as the next chairman. Nissan's board is due to vote on their choice Dec. 17.