General Motors Corp. (GMGMQ) said Friday that it had yet to find a suitable car to build at a Fremont, Calif., plant operated in partnership with Toyota Motor Co. (TM).

The New United Motor Manufacturing Inc., or Nummi, joint venture, launched in 1984, is threatened by GM's decision to end production of the Pontiac Vibe at the plant, alongside two Toyota models.

"So far, we've not figured out a product that fits the needs of [the partners]," said GM North America President Troy Clark during a conference call with reporters.

-By Doug Cameron, Dow Jones Newswires; 312-750-4135; doug.cameron@dowjones.com