Toro Rosso can count on stability through 2009 despite co-owner Dietrich Mateschitz looking to sell his stake in the Formula One team, Franz Tost has confirmed.

"The rumours regarding the sale of the team, when they grew stronger again earlier this season, did have an effect on us, but only for a short time," Tost said on Tuesday ahead of Sunday's British Grand Prix.

"If every week there is a story that the team will be sold it is not so funny for the employees.

"But the message we have from Dietrich Mateschitz is clear, that for 2009 everything will remain stable, not just in terms of employment but also in terms of the budget," Tost said in a preview for the race at Silverstone that marks the halfway point of the season.

"Then, from 2010 we will see what happens."

Mateschitz, the Austrian energy drink billionaire who also owns the Red Bull Racing team, said in March that Red Bull would sell their stake in Toro Rosso before 2010 because of an expected change in the regulations requiring all teams to build and design their own cars.

The current Toro Rosso and Red Bull cars are both designed by Red Bull Technology under former McLaren technical director Adrian Newey.

Formula Three competitors Ultimate Motorsport said last month that they were in talks to buy a stake in Italian-based Toro Rosso, whose other co-owner is Austria's former grand prix racer Gerhard Berger.

Tost said both his drivers, Germany's Sebastian Vettel and France's Sebastien Bourdais, were doing well.

"Vettel is doing a very good job because we can see his learning curve is increasing and he is getting better and better and I am convinced that in the next few races we will see the results of this," he said.

"Bourdais had a fantastic start in Melbourne and he has also had some other good races. He too is improving and we can expect to see more good races from him."