Singapore GP: Sauber in no hurry to decide 2013 F1 driver line-up

"In real terms there is no deadline," Kaltenborn said ahead of the Singapore Grand Prix. "Naturally there are a few key dates when it would be helpful for the development [of the car] if one knew who the drivers would be. But I believe we are still some way away from that."

She added: "There is no pressure. We are not in a hurry and nothing forces us to take a decision. But there is also nothing stopping us. We just plan to concentrate on this season."

Sauber driver Sergio Perez, who is in his second year with the team, has been linked with a more to Ferrari, although that has been ruled out by president Luca di Montezemolo.

Kaltenborn, whose team is enjoying its strongest season as a non-manufacturer outfit, insists it remains completely focused despite the rumours about its drivers.

"The speculation is no distraction. It is interesting that when one of our drivers has a good race the speculation starts; when he does not, nobody talks about it. Thus we always know exactly when the speculation will start."

Japanese driver Kamui Kobayashi is currently in 12th position in the standings and has been somewhat overshadowed by team-mate Perez this year.

Kobayashi says, however, that he is pleased with the job he has done, although he admitted he is still in the dark about his future.

"I have no idea. I don't know," he said when asked about his plans for 2013. "I'm happy with this year's job and with myself. Of course I've had a lot of bad luck, but usually I think this can happen. But we are improving, we are getting strong and we are getting results. But for next, I have no idea."