Renault team boss Eric Boullier said Romain Grosjean earned his return to the squad's Formula 1 line-up by achieving every goal set out for him this season.
Grosjean had previously raced for Renault in F1 in the second half of the 2009 season, as the team was embroiled in the Singapore race-fixing controversy, but did not impress and lost his drive at the end of the year.
He rebuilt his career in first World GT1 racing then GP2, where he took the Asia and main series crowns this year, while also becoming Renault's third driver in F1 and running in Friday practice in Abu Dhabi and Brazil.
Last week Renault - which will become Lotus next season - announced that it had decided to promote Grosjean back into a race seat alongside high-profile returnee Kimi Raikkonen for 2012.
"It's a challenging mission," said Boullier of his reasons for picking Grosjean over 2011 race drivers Vitaly Petrov and Bruno Senna.
"Romain has been with us for quite a few months now and he has had several aims to achieve from the personal, professional and sporting points of view. He had to find his footing again in a team which he left in what were certainly not the most reassuring circumstances.
"He achieved all these aims one by one until we decided to give him the opportunity to drive for us in free practice in the last two races of the season. He proved to the team that he had enough talent, speed and maturity to become one of the works drivers for next year."
Boullier acknowledged that Grosjean's French nationality went down well with team backers like Total, but said it was "absolutely not" the main motivation for his signing.
"It was just another point in his favour," said Boullier. "For our French partners like Total it's a godsend to be able to take advantage of his presence as one of our drivers."