Stuttgart - Mercedes motorsport director Norbert Haug said Friday that part of the reason the German car giant is supplying the new Brawn GP Formula One team is to ensure the same number of cars compete in 2009 as last season.

Ex-Honda team principal Ross Brawn's management-led buy-out of his former team, which pulled out of the sport last December, was announced by Japan's second largest carmaker Friday in Tokyo.

The team has agreed a partnership with Mercedes for the supply of its 2.4 litre FO108W Formula One engines and is hopeful that its driver line-up of Jenson Button and Rubens Barrichello will be on the grid for the season-opening Australian Grand Prix on March 29.

"We feel the continued existence of the team is unbelievably important. This, together with the financial aspects, was the reason we decided to cooperate at this late stage," Haug told Deutsche Presse-Agentur dpa.

"Formula One shouldn't only have 18 cars on the grid."

However, Mercedes is already supplying the McLaren-Mercedes and Force India teams and, according to FIA regulations, a carmaker should only supply two teams.

"Permission is required from the international ruling body FIA and hopefully the team will get it," said Haug. (dpa)