Aug.6 (GMM) Sauber has not decided if it will stay with Ferrari power in 2014.
The Swiss team has expressed grave doubts about the increased costs of renting engines for the radical new V6 regulations in 2014.
Before and after Sauber's recent BMW era, the independent Hinwil based team was and is a longstanding Ferrari customer, but the current agreement runs only to the end of the V8 era.
"It is obvious that we will go first to our current engine partner, because we have a long shared history," chief executive Monisha Kaltenborn told the German website motorsport-total.com.
"But it's all open, because I think they themselves (Ferrari) also do not know much more than us about certain conditions."
With the apparent demise of Craig Pollock's 2014 venture Pure, and the likelihood that Cosworth will bow out of F1 prior to the V6 era, Sauber's options appear limited to either Ferrari, Mercedes or Renault.
Kaltenborn continued: "We have made it clear that the financial aspect is very important for us.
"We do not want to go back to the days when you had to pay so much more money for engines."
Meanwhile, Kaltenborn played down rumours Sauber's salvation could be Volkswagen.
Her boss Peter Sauber recently confirmed he met at the Geneva motor show with VW chairman Martin Winterkorn.
"That's all there is, there's no more to say about it," Kaltenborn insisted. "We are not in further talks."