British-born Sam Bird drove for French team ART in 2010 and took part in the young drivers test in Abu Dhabi driving for Mercedes GP in November, while Sweden's Marcus Ericsson - who drove for Mercedes GP at the young driver test at Circuito de Jerez in December alongside IndyCar driver Mike Conway - will move from Super Nova Racing.
Bird finished fifth in the 2010 GP2 Series and won the Monza feature race in September, also taking three podiums and one pole position. After good consistency and some eye-catching performances in GP2, Bird was immediately in demand after ART opted not to retain him for 2011.
Ericsson - the 2009 Japanese F3 champion - won the sprint race at Valencia in June, but only managed to finish in 17th place in the overall GP2 driver standings. Ericsson's job prospects were buoyed by praise from Mercedes GP team principal Ross Brawn who said that the Swede had "performed very well showing exceptional maturity in his approach and feedback".
The duo will join the team in Abu Dhabi for the pre-season test days at the start of February, and will drive for the team in both the GP2 and GP2 Asia championships in 2011.
"I'm really excited," said Bird at the Autosport International Show in Birmingham where the announcement was made. "I think iSport has the engineering expertise to push me hard and I have a team-mate to push me hard," he said, adding: "I think we're ready for a title push now."
iSport International's pedigree includes running Timo Glock to the GP2 title in 2007, which saw the German then take the step into F1 with first Toyota F1 and currently Virgin Racing.