ART confirm di Grassi, Ammermuller

The duo will be in charge of defending both of ART's championship crowns.

"I am happy that Lucas and Michael join us for the coming season," said team boss Nicolas Todt.

"After two exceptional years, we are well aware the challenge to do as well as we did in 2005/06 will be very difficult, but I'm convinced drivers such as Lucas and Michael, thanks to their GP2 experience and their records, can help us to reach our goals."

Twenty-year-old Ammermuller will compete in the series for the second year running after finishing in 11th place with the Arden team in 2006, having scored one win and three podiums.

Brazilian di Grassi, 22, will also be in his second year of GP2. In 2006, he raced for the Durango team and finished in 17th position.

ART's Frederic Vasseur added: "Our aim for 2007 is to win both championships for the third time in a row and to achieve this end we wanted to run with two experienced drivers.

"Michael and Lucas have shown that they have  what  it  takes to handle the  pressure and to win races in a very competitive environment.

"We believe that both are potential championship winners. Many thanks to Red Bull and Renault for having made this 2007 project of ours possible."