Toyota Motorsport confirms it has reached agreement with Williams F1 to end its engine supply contract at the end of the 2009 Formula 1 season.
An extension of the contract, which began in 2007, was signed earlier this year but at the request of Williams F1, has been terminated by mutual agreement.
Tadashi Yamashina, Chairman of Toyota Motorsport, said: "We have enjoyed a productive working relationship with Williams and I believe both companies have benefited from that partnership. We respect the wishes of Williams to look for other opportunities and wish them well for the future."
Since the partnership began, Toyota engines have powered 10 podium finishes; three for AT&T Williams and seven for Panasonic Toyota Racing.