Williams has confirmed that Rubens Barrichello will remain with the team in 2011, and says it will annouce Nico Hulkenberg's replacement before the end of the year.
Team boss Frank Williams gave no reason for Hulkenberg's departure, but praised the German's rookie season.
"First, I would like to thank Nico for his hard work this year, and before that in preparing himself for Formula 1," Williams said. "We are very proud to have supported him as he secured the Formula 3 and GP2 titles and during his debut in Formula 1.
"At Williams, we have for many years tried to bring new talent into the sport - and we are convinced that Nico will go on to great things. We wish him well and hope that our paths will cross again in the future."
Williams added that he is happy to have secured the services of Barrichello for another year.
"We recruited Rubens knowing he would bring technical expertise, experience and passion," said Williams. "He has delivered everything we could have hoped for this season and we are delighted to confirm that he will drive for us again in 2011."
Barrichello finished 10th in this year's championship, with 47 points, and will extend his F1 starts record next year - during which he will turn 39.