Lucas di Grassi will take Allan McNish's Audi seat alongside Tom Kristensen and Loic Duval for the defence of their World Endurance Championship title, the German manufacturer has confirmed.
The Brazilian moves up as expected to a full-season ride in the wake of McNish's retirement after driving Audi's third car at last year's Le Mans 24 Hours and the Spa WEC round.
Audi Sport boss Wolfgang Ullrich said: "It's not easy to replace a driver like Allan McNish, who drove for Audi for 14 years, but Lucas di Grassi has delivered convincing performances in all of his runs for Audi so far."
Di Grassi also contested the Sebring 12 Hours American Le Mans Series round last year with McNish and Kristensen.
His deal for 2013 came after an impressive debut on a one-off appearance in the previous season's Interlagos WEC round, which came at the behest of event promoter Emerson Fittipaldi.
Italian Marco Bonanomi returns to the third car, which he raced in 2012, after being replaced by di Grassi ahead of last season.
The 28-year-old was initially dropped from Audi's roster of drivers for 2013 but was brought back into the fold to take a key role in early development of the latest version of the R18 e-tron quattro.
Bonanomi will share the third R18 with Briton Oliver Jarvis and Felipe Albuquerque, whose switch from DTM to the WEC was announced by Audi earlier this month.
Former grand prix driver Marc Gene, who has raced the third car for the past two years, steps down to a reserve role.
Audi has confirmed that 2012 world champions Andre Lotterer, Benoit Treluyer and Marcel Fassler will remain together for a fifth season.