Rubens Barrichello has re-signed with Williams, but team-mate Nico Hulkenberg is on his way out of the British Formula One team.
Barrichello, 38, has signed on for a second year with the UK constructor, meaning he will line-up for his 19th consecutive F1 season in 2011.
The Brazilian veteran became the first man to make 300 race starts at the Belgian GP in August and helped Williams to sixth place in constructors' championship.
The most experienced man in F1 joined Williams after one season with the now defunct Brawn GP in 2009.
Before that, he enjoyed six high-profile seasons alongside Michael Schumacher at Ferrari and also raced for Jordan, Stewart and Honda in his record-breaking career.
Hulkenberg, 23, earned his chance alongside Barrichello after two years as a test driver with Williams but will now depart after failing to agree terms on a new deal.
"I heavily regret that, because I would have been happy to stay with Williams," Hulkenberg said of his inability to negotiate a new contract.
"I want to thank the team for a great time and I wish Williams all the best for the future."
Hulkenberg's manager Willi Weber is reportedly in negotiations with a number of other teams in a bid to secure the German a drive for the 2011 season.
His former team principal, Frank Williams, thanked the outgoing man for his contribution.
"I would like to thank Nico for his hard work this year, and before that in preparing himself for Formula One," Williams said.
"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."