"Survivor" host Jeff Probst apparently does not need company.

CBS and the producers of "Survivor" are threatening to sue ABC and Granada Entertainment should the latter move ahead on staging an American version of the hit British series "I'm a Celebrity ... Get Me Out of Here!," Variety reports.

Executives at CBS say that "I'm a Celebrity," which would feature eight B- and C-list celebrities braving the Australian Outback to raise money for charity, is too similar to their show.

ABC reportedly ordered 15 one-hour segments of "I'm a Celebrity" earlier this month.

Lawyers for CBS have told ABC and Granada that they have until Wednesday to promise in writing "that they will not broadcast or license in the United States any programming based in whole or part on the 'Celebrity' series," reports Variety.

"We just received the letter and we're in discussions with Granada about it and will decide upon a course of action once those discussions are completed," ABC spokesman Kevin Brockman tells the trade paper.

The action comes just days after producer Bob Geldof commenced legal action in England against the producers of "I'm a Celebrity," saying the idea was stolen from his own production company's show -- the original edition of "Survivor," on which the CBS version is based.