Williams driver Ralf Schumacher signed a three-year deal with Toyota from the 2005 season, the formula one team announced on Wednesday.
"He has proven himself to be an extremely quick racing driver in his career, and I am sure that his vast experience will be extremely beneficial to our team," said team chief Tsutomu Tomita in a statement.
"We have not finalised who will partner Ralf in 2005 and this is something we are in no rush to decide on.
"We are happy with the job that Cristiano (da Matta) and Olivier (Panis) are doing for us and both of them are under consideration for the remaining race seat next season."
Ralf, the brother of world champion Michael, is currently out of action after fracturing his spine in the U.S. Grand Prix last month.