SINGAPORE: The controversial 'Singapore Sling' chicane at the Marina Bay Street Circuit remains one of the most dangerous in Formula One with further modifications required, world champion Sebastian Vettel said on Saturday.

The high kerbs on the 10th turn of the track have been toned down since Kimi Raikkonen went airborne late in the inaugural race in 2008, but the trickiness of the sharp left, then right by the old Supreme Court and Cricket Club continue to irritate the drivers.

Vettel managed to steer his Red Bull around the problematic corner without too much bother in dominating the three practice sessions but could only manage a disappointing third in qualifying for Sunday's Singapore Grand Prix.

Last year's winner appreciated that little could be done before Sunday's race but called on organisers to make the changes ahead of the sixth edition next year.

“We have discussed it many times, every year actually, but a better solution in turn 10,” the German told reporters after qualifying, headed by Lewis Hamilton with Pastor Maldonado second.

“It probably requires taking a little bit of land for those couple of days from the Cricket Club or maybe remove the pavement for three, four days.

“I imagine, if you consider the costs for this whole event, taking a pavement away and putting it back on shouldn't be a big problem,” he added.

On the same day organisers agreed a new-five year, S$150 million ($122.61 million) race contract to extend the unique night event through the streets of the wealthy southeast Asian city-state until 2017, they said they would listen to suggestions for track changes.

“In terms of safety, I think that is one of the worst corners we have in the calendar because you have these big kerbs, big bumps,” the 25-year-old Vettel said.

“It is a bit tricky to find a better solution right now with the space we have but I think that is something we need to work on,” he added, drawing a nod of agreement from both Hamilton and Maldonado.

The corner has not witnessed any crashes this year but many of the drivers in practice chose to drive through the apex of the chicane and skip the final bend.

Sauber's Kamui Kobayashi and Nico Rosberg in his Mercedes both struggled with the corner in practice, routinely bouncing over the kerbing.

Jenson Button, who will start alongside Vettel in the second row after finishing qualifying fourth in his McLaren, complained on Saturday that he could not see the corners of the chicane and that it was “pretty tricky, very bumpy”.