Kamui Kobayashi has conceded that he will not be able to secure a race seat at a competitive Formula 1 team for the 2013 season.
The Japanese driver has been trying to raise funds to get a drive for next season after being dropped by Sauber.
On his official website, the 26-year-old said: "I was in the position to bring a budget of €8m (£6.5m) at least. If you could imagine the time I had, it was overwhelming reaction and it shows there still is a great potential from Japanese companies.
"Unfortunately, the time was still short and I am not able to secure the seat with competitive F1 team for 2013. I have to admit that it is very sad and feel sorry for fans and Japanese companies who supported me. But I am still confident to make it happen in 2014.
"I would like to stop the donation for now and while I will save all the money for 2014, I start to look what is the best option for 2013 and also 2014. My main priority is to secure the competitive F1 seat in 2014. I have no interests to race any other categories."
As well as donations from Japanese companies, fans of the driver have been offering funds to keep him in the sport.
Kobayashi finished 12th in the drivers' standings this year, and secured his first ever podium finish at his home race.
