Williams has confirmed that GP2 champion Pastor Maldonado will be its second driver in 2011, taking the seat occupied by Nico Hulkenberg this season.
Maldonado had been extensively linked with Williams in recent months, and tested for the team during the recent rookie sessions in Abu Dhabi, where he also spent two days with Hispania. He is believed to bring significant levels of personal sponsorship to the team.
"I feel very privileged that Williams has selected me as one of their race drivers," Maldonado said. "It is a great way to end what has already been an amazing year for me.
"I tested with the team in Abu Dhabi, but can't wait to start working with everyone properly to be in the best possible shape going into next year. I will be doing my best over the winter to prepare myself, and I know the team will be working hard to ensure a successful season.
"2011 will be the first time in nearly 30 years that a Venezuelan has driven a Formula 1 car so I will be looking to get some good results in return for the support my country has given me to help get me to this position today."
The 25-year-old took the GP2 title with seven victories this year, but team boss Frank Williams said he had been watching Maldonado's progress since his first GP2 win in Monaco with the Trident team in 2007, when he had just moved across from the World Series by Renault.
"Pastor first caught my eye in 2007 when he drove a masterful race at Monaco," Williams said. "Since then, he has regularly reminded us of his unquestionable talent with some skillful wins, particularly during this year's GP2 championship, taking an unsurpassed record of six successive victories.
"Of course, we already know Pastor from the time he spent with the team at the Abu Dhabi test, but we are very much looking forward to developing his talent over the winter and a fruitful season with him next year."
Williams had already announced that Rubens Barrichello will be retained as its other race driver next season, with Valtteri Bottas remaining in the test and reserve role.