Singapore: Four-time world champion Sebastian Vettel on Thursday said it was "sad" to hear Renault was ending its partnership with Red Bull and urged the engine-maker to stay in the sport.
Vettel`s world titles with Red Bull were all powered by Renault engines but the relationship has soured to the point where the French company is about to walk away.
Chairman and CEO Carlos Ghosn this week said Renault would stop supplying engines to other teams and would either run its own outfit or quit F1 altogether.
"Obviously it`s sad to hear," Ferrari driver Vettel said ahead of the Singapore Grand Prix, when asked about Renault`s impending split with his former team.
"I was part of that partnership, we had very successful years which unfortunately now gets forgotten very quickly because of the situation.
"Renault has done a fantastic job in the past, supplying us with a strong engine, supplying us with the latest (engineering).
He added that he hoped Renault stayed in the sport.
Red Bull and Renault have fallen out during a disappointing season when the Austrian team has dropped well off the pace set by Mercedes, while consistently blaming its engines.
Engine-makers have grappled with the complex technology required by Formula One`s hybrid engines, which were introduced last year.
Renault are also pursuing a takeover of cash-strapped Lotus, who are fighting a court bid by British tax authorities to put them into administration.
"We have already alerted the F1 authorities and told them: `Don`t count on us as a provider of an engine - it`s over`," Ghosn said this week.
"Our future is the subject of detailed analysis and renegotiating," he added. "We will either exit or run our own team. We don`t have a clear decision yet."
After 12 races this season, Renault-powered Red Bull are fourth in the constructors` standings, behind Mercedes, Ferrari and Williams.