Pastor Maldonado will remain with Williams for the 2012 season but the identity of his team-mate next year remains a mystery, with Rubens Barrichello expected to leave.
Maldonado, 26, scored a single point in his first season but boss Sir Frank Williams believes he has potential.
"Pastor has proven he is not only quick but can also maintain a consistent and strong race pace," said Williams.
"He will play a critical role in 2012 as we rebuild and move forward."
Venezuelan Maldonado is confident he can make a bigger impact in 2012.
"I am convinced that the steps we have taken to improve our competitiveness will bear fruit in 2012 and beyond," he said.
Maldonado was partnered by Brazilian veteran Barrichello during 2011 but the former Ferrari man is almost certain to leave the team, potentially ending a Formula 1 career spanning 19 seasons and a record 322 starts.