Ross Brawn believes the future of Formula One racing remains bright despite the decision by Toyota to pull out of next year's championship.

The Englishman led his Brawn GP team to both the drivers' and constructors' World Championships this year at the first attempt, less than a year after he salvaged the team when Honda decided not to race.

BMW and Toyota have since joined the list of manufacturers pulling the plug on their Formula One adventure, while question marks hang over the future of Renault.

But Brawn believes the arrival of the Lotus, US F1, Campos and Manor teams on the grid in 2010 prove that the sport has a long-term future.

He said: "The economic situation has not been good for car manufacturers but it seems to have turned the corner now and most of them are reporting increased sales.

"There are lots of encouraging signs but there is a lag in time for companies to react as it takes a lot of money and time to commit to an F1 team so we may not see them return for a while.

"But there has always been a core group. Ferrari and Mercedes have ridden a few storms over the years but have always been involved and I don't see that changing.

"Some teams are leaving but they are being replaced and we still have a queue of smaller teams wanting to come in.

"I have been in F1 for over 30 years and have seen it go from privateer teams to big factories and back again and I think the future of the sport is strong.

"Some manufacturers use F1 just for the gains they get from it and others are in it for the long haul and we are seeing now who is who."

Brawn refused to be drawn on the future of world champion Jenson Button, who has yet to sign a contract to stay with the team.

The 29-year-old is believed to be seeking a return to the salary he commanded at Honda and has been consistently linked with a move to partner fellow Briton Lewis Hamilton at McLaren.

Brawn said: "There is still a 99 per cent chance that Jenson will be staying but we have nothing more to say at this time.

"But the team have been working flat out on the 2010 car since the summer so we are in good shape for next year and we expect to be in a real battle for the title again."