BRAZILIAN Formula One driver Rubens Barrichello has signed for Williams and will leave current stable Brawn GP at the end of the current season, Folha de Sao Paulo newspaper reported on Monday. <br><br>Barrichello, currently on a reputed $US2 million ($A2.21 million) annual salary, "has already signed a contract with Williams for the 2010 season with a mutual option to extend for another year", the paper said.<br><br>Williams will pay him "some four times more" plus win bonuses, the report added.<br><br>Barrichello is duelling with British stablemate Jenson Button for the championship as the season enters its final stretch with just Brazil and Abu Dhabi to come. He has 71 points to Button's 85.<br><br>Folha said that German Nico Hulkenberg, 22 and currently a Williams test driver, would be Barrichello's teammate next season.<br><br><br>http://www.heraldsun.com.au/sport/rubens-barrichello-joins-williams-gp-team/story-e6frf9if-1225786106144