Alexander Rossi will make his Formula 1 debut with Manor Marussia at this weekend's Singapore Grand Prix, alongside Will Stevens.
Rossi, currently second in the GP2 Series, will participate in five of the remaining seven races, stepping back to GP2 for its clashing rounds in Russia and Abu Dhabi.
Roberto Merhi, who has occupied the seat since the start of the year, will therefore return to Formula 1 for those two events, having been demoted to a reserve driver role at the outfit.
Rossi was Marussia's reserve driver during the latter part of 2014, prior to the outfit entering administration.
"I’m very thankful to race Manor Marussia and for their continued belief in me," said Rossi.
"I’ve been prepared for this opportunity for quite a while now. Many will know from 2014 that the team and I already have a strong relationship and there’s a bit of unfinished business for me here.
"This is a small F1 team that has been through so much. They exemplify passion and true strength of character, and their comeback this season is extraordinary. I’m honored to be part of this legacy and their continued growth and success.
"I want to thank the management at Manor Marussia and my team in the GP2 Series, Racing Engineering, for supporting both my F1 duties and the completion of an already strong GP2 campaign.
"Since Monza, my return to F1 came together rather quickly and seamlessly. The collective support of both Manor and Racing Engineering was instrumental in making this opportunity possible."