Sauber's Monisha Kaltenborn wary of Formula 1 manufacturer tie-up

The independent Swiss team was sold to BMW in 2005, racing as BMW Sauber between 2006 and '09 and winning the Canadian Grand Prix with Robert Kubica in '08, when it finished third in the constructors' championship.

The team's future was cast into doubt when the German manufacturer pulled out of F1 - at the same time as Toyota and 12 months after Honda - before being saved when it was sold back to founder Peter Sauber.

Sauber was among the initial candidates for a potential Renault buyout earlier this year, and while Kaltenborn said the team would like to have a partner again, the positives of a deal would have to be weighed up against the negatives.

"The target has to be to have a strong partner," Kaltenborn told AUTOSPORT.

"One has to be always very cautious with engine manufacturers and becoming a works team.

"It has a lot of positives but at the same time, and this is nothing negative, but this is a marketing tool where you show your technical excellence if you're a manufacturer.

"When you achieve that and you achieve that a couple of times - and I exclude Ferrari here, because they have a different bond to the sport - you have achieved your target and then you leave.

"Equally the other way around, you have to win. That's the only thing you can do as a manufacturer team - number two is already a loser to them.

"If winning does not happen they have also, as we have seen, quit the sport.

"The important thing is to have a strong partner who has a longer term view on the sport, irrespective of where you stand."

Kaltenborn pointed to strong relationships the team has had in the past as reason to want to pursue similar partnerships in the future.

"We're always open and we get requests in," she said. "We are open to a partnership like that because it makes you stronger.

"We have had strong partners, not just manufacturers. We had Petronas for a very long time.

"We had BMW who bought a majority in the team and the same with Red Bull. So we are absolutely open for that."