Even after a relationship is dead, couples often go through the motions of remaining in a marriage. That's the best way to characterize what's left of the alliance between Renault SA and Nissan Motor Co.

Renault must sell down its 43.4 percent stake in its Japanese partner to 5 percent-10 percent and both sides should "invest in new ventures," Nissan's Senior Vice President Hari Nada wrote in an e-mail to colleagues, saying this was the view of independent director Masakazu Toyoda, the Wall Street Journal reported at the weekend. In Toyoda's view, the two sides should come up with some sort of joint venture in order to show that the alliance isn't dead, giving Renault Chairman Jean-Dominique Senard the room to unwind the cross-shareholdings that underpin the relationship, the Journal reported.

To judge by the picture this paints of discussions within Nissan, the firm is only interested in maintaining the appearance of an alliance with Renault and its 15 percent shareholder, the French government. Making a joint commitment to reaffirm a bond isn't uncommon for people in a failing relationship, but it's no way to run a business.