The billionaire CEO says both boards have formed special committees to weigh a combination that would unite the world's most valuable automaker with its dominant private rocket company.

On SpaceX's second-ever earnings call, Elon Musk said both companies formed special committees to explore a combination, with no terms agreed.

Special committees at both companies are assessing a Tesla-SpaceX combination, but Elon Musk says the deal is far from guaranteed, leaving shareholders to weigh the upside against the uncertainty.