Tech billionaire Elon Musk on Tursday said a merger between his two companies, SpaceX and Tesla, would be a "good idea" and that they had formed special committees to discuss the matter — confirming speculation of a possibly union.

"I think it would be a good idea, but it's really up to the special committees of both companies," Musk said.

"Because ​I'm a conflicted party, I can't actually be in the discussions of the special committees," which was comprised of independent directors, he told investors on a conference call.

Shares of the space tech company rose 8% in trade over Musk's comment, while Tesla's shares rose 1.8%.…