Felipe Massa has announced he is retiring from Formula 1 for a second time at the end of the season.
The 36-year-old departed at end of 2016, however, Williams tempted him back into the cockpit after Valtteri Bottas was drafted in at Mercedes after Nico Rosberg unexpectedly announced his own retirement after winning the world championship.
Paired with Lance Stroll for 2017, the Brazilian driver had led the teenager all season but now finds himself behind his team-mate in the points standings for the first time this year, despite having a successful start to the season.
Massa said: “As everyone knows, after announcing my retirement from Formula One last year, I agreed to return this season to help Williams when the call came. I have now enjoyed four great years with the team, but my career in Formula One will finally come to an end this season.
“I take so many great memories with me as I prepare for my final two races in Brazil and Abu Dhabi, and although they will be emotional, I am looking forward to ending on a high note and preparing for a new chapter in my career.”
Massa has won 11 races, 41 podiums 16 pole positions so far and fought against Lewis Hamilton in a hotly contested 2008 world championship, which saw both drivers take the battle right to the very end of the season in dramatic fashion.
Deputy team principal Claire Williams added: “I would like to thank Felipe for all he has done for the team over the last four years. It has been an absolute pleasure to work with him.
“We are especially grateful that he agreed to postpone his retirement from Formula One for a year, after Valtteri joined Mercedes, which demonstrated the depth of the relationship we built during our time together.
“We appreciate that it wasn’t an easy decision for him to return, after having such an emotional send-off at the end of last year. On behalf of Sir Frank, and all the team, we give our very best wishes to Felipe for the future.”
Williams has stated there is no rush to announce their line-up for the 2018 season, potential candidates in Robert Kubica, Paul Di Resta and Pascal Wehrlein are being looked into. Even ex-Toro Rosso driver Daniil Kvyat has been linked with a move to the Grove-based outfit.