Wolff casts doubt on Senna future at Williams LONDON (Reuters) - Williams want penalty-prone Pastor Maldonado to stay with them next season but Bruno Senna's future with the Formula One team is less certain, influential shareholder and executive director Toto Wolff indicated on Tuesday. The Austrian, increasingly cast as the eventual successor to team principal and founder Frank Williams, told the official Formula One website (www.formula1.com) ahead of Sunday's Singapore Grand Prix that a decision on drivers for 2013 was still some way off. "We are taking different looks at the issue, but the minute we discuss it we are going to mess up Pastor and Bruno - and maybe others that we try talking to," Wolff said when asked whether Williams would stick with the same lineup. I would give it another month before we are going to have the first idea of what we want. Williams have highly rated Finnish youngster Valtteri Bottas as their test and reserve driver, who also has management links to Wolff and would be a well-placed internal candidate to step up to a race seat. Bottas has taken part in several Friday morning practice sessions this season. Venezuelan Maldonado brings substantial sponsorship with him from his country's state oil company PDVSA and is also a race winner after his pole-to-flag victory in Spain this year, former champions Williams' first triumph since 2004. However, he has also been involved in a spate of incidents that have led to numerous starting grid penalties and cost the team precious points. Wolff, who works closely with Frank Williams and took on the executive director role in July, made it clear that he expected Maldonado to stay and lead the team further up the grid. In 2013 we will have a carry-over of the car so I'd like to see us in the points more regularly. Pastor hopefully stays with us and has learned his lessons - so the next logical step would be the top six in the constructors' - or even top five," he said. Wolff said Maldonado had a "huge raw talent," was extremely fast and also an intelligent driver who realized he needed to take a different approach. Maybe Pastor has to change the way he is driving and he has accepted that. So we take it from there. I am sure we will see many more successful races from him in the future," added the Austrian. His comments on Brazilian Senna, nephew of the late triple champion Ayrton who died in a Williams in 1994, were less effusive. Bruno is very intelligent and very sensitive and that means he is putting a lot of pressure on himself. Whether it is the name or not, I don't know," he declared. Every racing driver in F1 is very competitive and Bruno is trying to fight the fact that he hasn't had a huge racing education, as the family didn't want him to go racing. But he has made his way into F1, which means that he is good. He has an extremely fast team mate and he needs to follow his path. He is pushing very hard and we are trying to support him as best we can. Williams are currently eighth in the 12 team championship, nine points behind Force India. Maldonado has scored 29 points to Senna's 25. Reporting by Alan Baldwin