Nissan Motor Co. is opposing renewed efforts by alliance partner Renault SA to merge under a holding company because such a structure won't help turn it around, according to a source with knowledge of the discussions.

Talks have been ongoing since Renault Chairman Jean-Dominique Senard first made an informal proposal to Nissan Chief Executive Officer Hiroto Saikawa in April, the source said, asking not to be identified because the discussions aren't public.

Nissan rebuffed the idea then and has continued to oppose it, the source said.