Brawn GP chief Ross Brawn says he believes that Japanese companies will return to F1 once the current financial situation improves, although it isn't a move that will happen anytime soon.

The last twelve months have seen the two major Japanese car makers quit the sport, with Honda pulling the plug on its programme at the end of 2008 and Toyota following suit just days after the conclusion of the 2009 season.

The car manufacturers aren't the only companies to have decided to exit the sport, with Bridgestone having also confirmed it will leave F1 at the end of 2010 but Brawn - who saved the Honda team and went on to secure both titles this season - insisted that the Japanese would return in future.

"They've obviously decided that this is how they need to respond to difficulties they are facing," he told Reuters, "but they have got a lot of history in Formula One, particularly Honda and Bridgestone, so let's hope.

"It will take a while, it's going to take a few years but Honda's was their second or third involvement in Formula One. Manufacturers look at the value to them of Formula One, there's no sentiment I'm afraid. So when it's viable they come in, and when it's not they don't."

With BMW joining Honda and Toyota in bowing out of F1 and a raft of newcomers set to join the grid, the grid will feature just three major manufacturers in 2010 in the shape of Ferrari, Mercedes and Renault but Brawn added that it was simply the cyclical nature of the sport - as teams and manufacturers come and go over time.

"It's a major sport and it (manufacturer involvement) will come round again," he said. "But luckily there is a lot of interest from privateers and they will sustain Formula One for a good few years. I've been in Formula One for over 30 years and I've seen it go from total privateers to a huge number of manufacturers back to privateers and it just goes in cycles depending on the climate.

"There has always been a core group. Ferrari have always been involved and Mercedes have a long history of being involved and riding the occasional storm. I think there are some manufacturers that take a day-to-day view and unfortunately those are leaving now but they are being filled up by a lot of private teams."