“And what better place to start off this new stage of my life than in Mexico where everybody has supported me so much.
“I want to thank (team boss) Jerry Forsythe and his Team for believing in me, I know it's not going to be easy but I've been waiting for a long time for this great opportunity and I'm going to make the most of it.”
Martinez' debut comes after two years in the ChampCar Atlantic Series in which he has finished fifth overall in both 2005 and 2006. He has also previously driven in A1GP and in the Formula Renault V6 Eurocup.
Martinez will partner team regular Paul Tracy and newcomer Buddy Rice in Mexico City.