Valtteri Bottas has been promoted to race driver for the 2013 Formula One season as he will line up alongside Pastor Maldonado at Williams.
Venezuelan Maldonado has retained his seat with the Grove-based marque for a third year, while Bottas, who has been the team's reserve driver for the past two seasons, replaces Bruno Senna.
It had long been suggested Bottas would get his chance in 2013 after impressing in a number of Friday practice sessions this year.
"In Pastor and Valtteri we have two of the most exciting talents in motor racing and I am especially excited about what 2013 can bring for Williams," team principal Frank Williams said in a statement.
"Pastor has always demonstrated remarkable pace and this year has seen him mature as a racing driver. Valtteri is quite simply one of the most talented young racing drivers I have come across and we expect great things from him in the future."
The 23-year-old Valtteri, a protege of McLaren's double world champion Mika Hakkinen, has been groomed by Williams over the past two years and his lap times during race weekends this season have been impressive.
He was even being linked to McLaren as a possible replacement for departing 2008 world champion Lewis Hamilton.
"It has always been my life-long dream to compete in the Formula One World Championship," he said.
"To do so with one of the most legendary teams in the sport is incredibly special."