Eric Boullier out as McLaren reshuffle leadership
McLaren racing director Eric Boullier has left the team, saying it is "the right time to step down" amid a wider restructure of their leadership.
McLaren have had a disappointing start to 2018, struggling to qualify in the top 10 having started the season with ambitions of competing with Red Bull.
Former Indycar champion Gil De Ferran has been appointed sporting director.
Andrea Stella has been appointed performance director, responsible for trackside operations.
McLaren chief executive Zak Brown said Stella - the former Ferrari engineer who joined in 2015 alongside Fernando Alonso - would be "ultimately responsible for the performance of the car" and would lead the team at the track.
Brown added that he had consulted closely with lead driver Alonso, who had been "a part of the process", and that the two new appointees will work closely to "maximise the performance of the team".
'Change to improve systemic issues'
De Ferran, 50, began a role as a roving adviser at the Spanish Grand Prix in early May. The Brazilian also acted as Alonso's driver coach during the Spaniard's attempt at the Indianapolis 500 last year.
Previously, he was sporting director for the Honda F1 team, which has since become world champions Mercedes, for two years from 2005.
Brown said that the performance of the car this season "has not met the expectations of anyone at McLaren, especially our loyal fans".
He added: "The causes are systemic and structural, which require major change from within. With today's announcement, we start to address those issues head on and take the first step on our road to recovery."
Boullier had been responsible for setting up the technical structure, which had begun to be questioned by McLaren senior management.
The 44-year-old said last season that their chassis was among the best in F1 and that they were being held back by the Honda engine.
McLaren decided to split with Honda, which was their works partner and provided free engines, sponsorship and other payments, at the end of last season and instead become a Renault customer team despite the moving costing in the region of $100m net per year.
However, the car has been close to two seconds a lap off the pace this season, with McLaren fifth in the championship and Alonso eighth in the drivers' championship.
Brown said McLaren had found themselves in "a completely unacceptable situation".
He added: "We have big performance issues. We are punching well below our weight given our history, and the resources, people and technology at our disposal.
"Ultimately Eric felt in order for McLaren to go forward in the best possible light, his resignation would allow that to happen.
"The situation was not created overnight and it will not be solved overnight but this is a great starting point."
A McLaren statement added that the changes were "the beginning of a comprehensive programme of positive changes to the technical leadership".
Meanwhile, Red Bull have announced that they are to stop using Renault engines at the end of this season and switch to Honda for 2019.