Heidfeld still pushing for F1 seat in 2012
The German veteran has been ousted at Renault but despite attending the weekend's German touring car round at Oschersleben he said F1 remains his target for 2012.
"There are still a few places, but not many," the 34-year-old told the German broadcaster ARD. "As long as there is a chance of a formula one cockpit, I will work for it."
Heidfeld revealed that he will travel to Singapore this week.
"I will be asking around a bit to see what is happening for next year," said the 13-time podium sitter, who has also driven for Prost, Sauber, Jordan, Williams and BMW.
Heidfeld raced in F1 with BMW power for five years, triggering rumours he will reunite with the German carmaker in DTM next year.
"About a possible future in the DTM, I do not want to speculate," he said on Sunday.
"Of course there are still the contacts but it's still too early to talk about it," added the German.
"Naturally DTM is at the highest level of motor sport but my goal is to be again in formula one next year.
"This year didn't turn out as I had hoped but I think what I've done in the past until now has been for a good reputation. Unfortunately many cockpits are gone but I will try to get a good seat," said Heidfeld.