Belgian driver Stoffel Vandoorne will leave McLaren at the end of the season, the Formula One team said on Monday.
The 26-year-old Vandoorne has raced in 34 Grands Prix since his debut in 2016, but he has struggled this season and is 16th in the standings with just eight points.
His departure means McLaren will have two new drivers for the 2019 campaign with Fernando Alonso set to retire from F1 at the end of the year.
"I'm very grateful to McLaren for investing their faith in me over the past five years," Vandoorne said.
"While we haven't achieved the success we'd all hoped for, I've really enjoyed the past two seasons racing for McLaren and I have a great relationship with everyone in the team.
"I intend to give it my all for the remaining seven races of this season, and will announce my plans for next season in due course."
Vandoorne's exit could lead to McLaren's reserve driver Lando Norris taking his place next year.
England's Norris, 18, has taken part in practice at the last two races in Belgium and Italy for McLaren.
Vandoorne replaced Jenson Button at McLaren for the 2017 campaign.
But despite a steady opening season in Formula One, he has struggled recently, being beaten in qualifying by Alonso at every round this term.
Vandoorne was last on the grid for Sunday's Italian Grand Prix before he took the chequered flag in 12th.