Dave Ryan has claimed that he is joining Manor Marussia "at a pivotal time in their development".

The former McLaren man will become the team's racing director, with current bosses Graeme Lowdon and John Booth leaving the constructor at the end of the season.

However, Ryan has warned that there is still a "big challenge ahead" for Manor, as they try to move up the Formula 1 grid.

In a team statement, Ryan said: "Having spent time with Stephen [Fitzpatrick] and understood his vision for the future, it is clear he has ensured there is a strong platform from which the team can make big steps forward in the seasons ahead.

"Manor has all the hallmarks of a fiercely competitive racing team, but having grown up in a much more contemporary Formula 1 era, it is a very lean operation with a collaborative culture, which leaves it well placed to contend with the sport's future direction.

"There is clearly a big challenge ahead and a lot of work to do, but I can't wait to meet the wider team and get down to business."

Manor have agreed to run Mercedes engines from next season.