The Toyota F1 team will join Williams in switching to Bridgestone tyres from Michelin next season.
Toyota, who were fourth in this year's championship, have agreed a long-term deal with the Japanese tyre company.
Bridgestone now has three strong teams after relying on Ferrari to do the bulk of its testing in recent years.
Toyota boss Tsutomu Tomita said: "We are serious about winning in F1 and we feel the switch to Bridgestone is the best option in the medium-long term."
Bridgestone struggled in 2005, winning only the six-car US GP which turned into a fiasco after Michelin-equipped teams withdrew for tyre safety reasons.
The FIA has changed the rules for 2006, however, with tyre changes allowed again after a year in which teams were forced to make tyres last for both qualifying and the race.
Bridgestone were dominant with Ferrari in 2004, when frequent tyre changes turned races into a series of sprints.
F1 is also due to have a single tyre supplier from 2008, and possibly 2007 if an 80% majority of the sport's technical working group can agree on a package of measures by the end of this year.
Bridgestone have said it is committed to F1 while French rivals Michelin have criticised the rule changes and hinted it could quit in 2007.