JENSON Button was today dreaming of becoming Formula One world champion after securing a high-profile move back to Williams.

Button has signed a two-year contract to race for Williams from next season, after current employers BAR failed to take up an option to extend his stay.

The 24-year-old Englishman, who currently lies third in the drivers' championship with 61 points from 12 races, will join the recently recruited Mark Webber.

"I am very pleased that I had the option to rejoin the team where my Formula One career started," Button said.

"I have every confidence that the massive investment in resources, and the depth of talent at Williams F1 and BMW, provides the best platform for my ambitions to be a world champion." Tweet