World champion Michael Schumacher says he is ready to continue in Formula One beyond the end of his current Ferrari contract in 2006.

But the record six-times world champion said the time to quit would come if his team mate, currently Brazilian Rubens Barrichello, was quicker than him.

"I have never excluded continuing after 2006," Schumacher told a news conference at the team's winter retreat in the Dolomites.

"When we extended the contract to 2006, the president (Ferrari's Luca di Montezemolo) told me: 'Stay as long as you like, as long as you are motivated and quick'.

"There is no reason to close doors for the future. If I feel then as I do now then it is an open future," added the 35-year-old German.

"There is no lack of motivation. I still enjoy it, we have a great team morale, great atmosphere within the team. We had a tough end to the year and it showed to all of us what is needed to finally succeed and actually I think that helped a lot with the motivation of the whole team.

"For me it is easy -- I love what I am doing, I love the sport, love preparing for races. For me there is no question about not being motivated and it is important that everyone around has the same motivation and from what I have seen over the winter I am not concerned at all," he said.

Schumacher welcomed Ferrari's decision to extend Barrichello's contract until 2006.

"Honestly, there is no better choice than Rubens to be with us," said Schumacher who described the decision announced this week as "natural and logical."

But the German said that while he would carry on as long as he was competitive, he would know the time to quit had arrived when he was no longer the quickest man in the Ferrari team.

"When I talk about competitiveness then I am talking about straight comparison," he said. "The only straight comparison I can draw is when I fight against my team mate.

"Should there be the day when I am doing my best and my best is not good enough, to be quick enough, against my team mate and I'm talking about being really too slow…then that is the day to stop honestly because then it becomes maybe dangerous."

The German said a faster rival from another team would merely prompt him and Ferrari to try harder.

"Whether there is another competitor being for whatever reason quicker, I'm talking about other teams, then that is not a problem," he said.

"That is our job as a team to fight back and do it even better than they do. If you look through my career I have had ups and downs, and had those periods, good periods difficult periods and usually the good period comes back.

"Our aim is obviously to keep the good period we are in as long as possible," he added.

Schumacher said he expected the 2004 season to be another hard battle.

"I think it is going to be another interesting year," he said. "As we all saw last year, it was tight and I think it will be tight again this year. In which direction and for whose favour is something we have to find out. But I have no worries that Ferrari won't be there."