Inside F1: Will Red Bull & Renault will split?

Renault is considering pulling out of F1 following criticism of its engines.

However, the French firm, which supplies engines to Red Bull and Toro Rosso, is also contemplating buying a team and becoming a constructor again.

"We are looking at a lot of options, including getting out of Formula 1 if it's bad for Renault's reputation," said the team's chief, Cyril Abiteboul.

Renault engines powered Red Bull to four successive world championships, before Mercedes won in 2014.

However, the manufacturer has come in for criticism since Mercedes dominated the season-opening Australian Grand Prix on 15 March, with Red Bull finishing a lap down on winner and world champion Lewis Hamilton.

Hamilton sets practice pace in searing heat

Abiteboul added: "We think we are a credible player in the sport but you need to think about what else we need to do on top of what we already are. But right now, the focus remains on the engine."

Renault only supplies engines to Red Bull and its sister team Toro Rosso after Caterham folded and Lotus switched to Mercedes.

When asked about speculation that Renault could buy his team, Toro Rosso's team principal Franz Tost said it would be a "fantastic opportunity" for the Italy-based team.

"To be owned by a manufacturer would be exactly the step forward which the team needs," added Tost, who was sitting next to Abiteboul.

Abiteboul's comments at the Malaysian Grand Prix indicate growing tensions between Red Bull and Renault.

Red Bull chief Christian Horner insisted the relationship was "super" but, in the build up to the trip to Malaysia, Abiteboul accused the Milton Keynes-based team's designer Adrian Newey of lying after he blamed the car's problems on the engine.

Malaysian GP practice results

Malaysian GP coverage details

Chief F1 writer Andrew Benson "The relationship between Red Bull and engine supplier Renault is clearly at its lowest ebb and it's hard to believe it's only a little over a year since they were celebrating their fourth consecutive title double together. "Both sides have valid points. Renault have been left behind by Mercedes and Ferrari on engine performance. But equally the latest Red Bull seems not to be the team's best-ever product and Adrian Newey does have a history of being dissatisfied with engine partners, whoever they are. "But it's hard to see the endgame here. "Renault are scouting around with one eye on buying a team and running one themselves again. But where would Red Bull go for an engine if not Renault? Mercedes have already said no and Ferrari would probably not be keen either. "It's not impossible that the threats made after Australia that Red Bull might quit the sport are less empty than initially believed, although they, like all teams, are contracted to F1 until 2020."

Relations between Renault and Red Bull have become strained