Bernie Ecclestone revealed on Thursday that he is in talks with two parties interested in the FIA's invitation to fill the final spot in pitlane.
It emerges that one of them is Gene Haas, a Nascar team owner.
"We have responded to the FIA's 'call for expression of interest'," he said, "and will share more details in the coming weeks."
Haas co-owns the Stewart-Haas team, and reports said he has an estimated net worth of $740 million.
It is claimed his team would be based in Charlotte.