Twenty-three-year old Grosjean, who was born in Geneva, will race alongside Fernando Alonso at the European GP in Valencia, Spain and for the remainder of the 2009 season.

In a statement, Renault said Piquet had been released from his obligations to the team "with immediate effect" following a "mutual agreement that this course of action is in the best interests of both parties."

Piquet had failed to score a point over the first ten races of the season and had publicly lashed out at team boss Flavio Briatore two weeks ago.

"This season Romain has been the team's third driver and has attended all races, which has allowed him to gain experience and become fully integrated with the team," Renault said.

Grosjean became part of the French team's driver development programme in 2006 after winning the French Formula Renault title.

In 2007, he was Formula 3 Euro Series champion, and in 2008 he won the GP2 Asia Series.

This season he has been competing in the GP2 Series with Barwa Addax.

"Impressive young talent"

Team director Briatore said Renault was "happy" to give Grosjean the chance to race with the team.

"He is an impressive young talent and we expect him to show his skills driving alongside Fernando as we take an aggressive approach to the second half of the season," Briatore said.

"We would also like to thank Nelson for his contribution during the time he has been with us and wish him all the best for the future," he added.

Grosjean commented that he was "proud" of the opportunity given to him.

"It's also an honour to be Fernando's teammate, and to make my Formula One debut alongside a double world champion is especially motivating."

Earlier this year, Grosjean said that becoming the third driver for the Renault F1 team was another step forward in his career.

"Learning experience"

"The year ahead therefore promises to be an amazing learning experience and I intend to make the most of the opportunity to be part of a world championship winning team."

"In 2008 I had my first test with the team and so I've been able to build a relationship with the test team, which has been a really valuable experience.

"Now, I'll be able to strengthen my relationship with the engineers and learn more about how the team operates, which is really exciting."

Another Swiss driver, Sébastien Buemi, entered Formula One this year and has been driving for the Toro Rosso stable.

swissinfo.ch and agencies