Felipe Massa is to retire from Formula 1 at the end of this season.
The Brazilian intended to quit F1 at the end of 2016 but returned to Williams after Valtteri Bottas moved to Mercedes following the retirement of world champion Nico Rosberg.
Massa, who has won 11 grands prix, says this time his decision is final.
The 36-year-old's decision was influenced by the fact he wanted certainty on his future before his home grand prix next weekend.
The Brazilian intended to quit F1 at the end of 2016 but returned to Williams after Valtteri Bottas moved to Mercedes following the retirement of world champion Nico Rosberg.
Massa, who has won 11 grands prix, says this time his decision is final.
The 36-year-old's decision was influenced by the fact he wanted certainty on his future before his home grand prix next weekend.