Mercedes is "leaving the door open" to supplying Red Bull with engines in the future amid rumours a deal could be brokered via luxury car brand Aston Martin.
Red Bull's relationship with its current engine supplier Renault is becoming increasingly frosty after a second season of substandard results under the current engine regulations. Aston Martin is 5% owned by Mercedes, and according to motor industry magazine Autocar, Mercedes could replace Renault as Red Bull's engine supplier in exchange for Aston Martin becoming a brand partner of the F1 team.
When Mercedes boss Toto Wolff was asked about the prospect of supplying engines to one of its closest rivals in recent years, he hinted that a deal would be possible in the right circumstances.
"There are many things to be considered," Wolff said. "What happens if Renault decides to have its own team and buy another team? Will they continue to supply Toro Rosso and Red Bull, and if not what are the solutions? Who is going to supply them in order to make sure they stay in the sport?
"What does it mean for us, because until now they were the enemy? Maybe there is a new enemy. What does it mean in the great scheme of things in politics and the balance of things? There are no discussions and there are no discussions ongoing and nothing has been started, but you need to consider all the options.
"I'm leaving the door open."
The Autocar story makes the link with Red Bull via Aston Martin's boss Andy Palmer, who was involved in negotiating Red Bull's current title sponsorship deal on behalf of Infiniti. But Red Bull boss Christian Horner has described the most recent rumours as speculation.
"Andy Palmer was here this weekend on a Force India pass," he pointed out. "The fact is we have a contract with Infiniti and Renault to end of 2016. Anything beyond the end of that agreement I pure speculation.
"Last week it was Ferrari, this week it is Aston Martin, next week it'll probably be Honda or Lamborghini, so there is a lot of speculation. There is a contract and a commitment with Infiniti and we have a very good relationship, so anything beyond 2016 is purely speculative."