Romain Grosjean has announced he will be leaving Haas at the end of the season.
Grosjean, 34, has been with the American team since they entered Formula One in 2016.
It is expected that Haas are poised to announce an overhaul of their current driver line-up for 2021, with the future of Grosjean's team-mate Kevin Magnussen also in doubt.
Frenchman Grosjean has made 175 starts in F1 but the concluding six races of the season are set to be his last in the sport.
"The last chapter is closed and the book is finished," said Grosjean in a Facebook post ahead of this weekend's Portuguese Grand Prix.
The last chapter is closed and the book is finished. I've been with Haas F1 Team since day 1. Five years during which...
Posted by Romain Grosjean on Thursday, October 22, 2020
"I've been with Haas since day one. Five years during which we went through highs and lows, scored 110 points in 92 races, but the journey was worth it. I've learned a lot, improved to be a better driver as well as a better man.
"I hope I've also helped people in the team to improve themselves. This is probably my biggest pride, more than any of the crazy first races in 2016 or fourth at the Austrian GP 2018. I wish the team all the best for the future."
Grosjean first competed in Formula One in 2009 with Renault for seven races before returning for his current spell in the sport at the end of the 2011 season with Lotus.
His best season was in 2013 when he finished in the drivers' championship, scoring six of his career 10 podium finishes.
After struggling last season, Haas' form has not picked up in 2020, with Grosjean only scoring his first two points of the season at the Eifel Grand Prix two weeks ago, the 11th round of the campaign.
