"We are in negotiations but it's not done yet -- done meaning when you sign the deal," the Italian told Reuters in a telephone interview.
"But we are working to finalise it this week and supply the engine to Red Bull."
Briatore said the deal would be with the Red Bull parent company rather than Red Bull Racing, who have a Ferrari contract for next year but want to shift those engines to Italy-based sister team Toro Rosso.
"After that it is a decision for (Red Bull owner Dietrich) Mateschitz and (Toro Rosso co-owner) Gerhard (Berger) to decide if its Red Bull or Toro Rosso," said Briatore.
Toro Rosso are currently using restricted Cosworth V10 engines inherited from Minardi, the struggling team bought by Mateschitz last year.
Renault do not currently supply anyone else but have said they want to help privately-owned teams secure competitive engines.
"The manufacturers need to support the private teams," said Briatore. "So we try to apply this gentleman's agreement."
