PARIS, FRANCE (Reuters) - French carmaker Renault will decide by the end of the year whether to stay in Formula One after a race-fixing scandal that has badly damaged the team's reputation.

"You will have to be patient," Renault Chief Executive Carlos Ghosn told reporters on Thursday."We will make an announcement on our participation in Formula 1 before the end of the year."

Renault ended the 2009 season racing under a suspended permanent ban for its involvement in a race-fixing controversy which resulted in its former principal Flavio Briatore being barred for life.

The team won the 2005 and 2006 championships with Fernando Alonso but the Spaniard has now left for rival Ferrari. Title sponsor ING has also departed, leaving a big hole in the budget.

Renault told F1's governing body in September that it wanted to stay in the sport after the team was found to have ordered driver Nelson Piquet to crash deliberately at last year's Singapore Grand Prix to help Alonso to win the race.

But the high costs and recent negative publicity might persuade the firm to join the growing exodus from the sport.

Toyota announced on Wednesday that it was quitting F1, less than a year after Japanese rivals Honda pulled out and only days since BMW said farewell in the season-ending Abu Dhabi race.

Sole tyre supplier Bridgestone has also said it will leave at the end of 2010.

Toyota's pullout meant Renault was one of only three manufacturers left in F1, alongside Ferrari and Mercedes.

Renault have signed Poland's Robert Kubica as one of their 2010 drivers but paddock gossip even before last weekend's season-ending Abu Dhabi Grand Prix suggested the manufacturer was considering selling all or part of the team.

The carmaker also supplies engines to Red Bull, runners-up to Brawn GP and winners of six races this year.