Sebastien Loeb will compete in the next two rounds of the Formula 1-supporting Porsche Supercup.
The nine-time World Rally champion will join the field for the Barcelona and Monte Carlo events.
Loeb has switched to circuit racing for his full-time campaign this year.
He is racing a McLaren for his own team in the FIA GT Series, but was keen to add more events as that championship's calendar is only six rounds.
Although Loeb has been a frontrunner from the outset in FIA GTs, he warned not to expect too much in the Porsche series.
"Porsche Supercup is another step above: I'll be racing alongside specialists with whom it will be difficult to rival," he said. "I know Barcelona a little, but I've never driven at Monaco.
"I want to drive as much as possible on circuits and learn as much as I can. Without a doubt, they will be two very enriching races, in that I'll be in the middle of a grid that will be animated and racy.
"It's also an opportunity to enjoy myself. Besides the driving, these are fun events since they take place alongside F1 weekends.
"There will be the pleasure of racing, but also the pleasure of experiencing the two grand prix, including Monaco, which is always special."
The races will mark Loeb's Supercup debut, but he has made occasional guest appearances in the French Porsche Carrera Cup since 2008. Last year he won both rounds on the Pau street circuit.
A week before Barcelona, Loeb will make the third of his four planned WRC appearances with Citroen this year when he contests Rally Argentina.
After that, he is not scheduled to contest any more WRC events until his home round in France in October, although he will keep his hand in rallying by contesting the Pikes Peak Hillclimb for Peugeot.
Alongside his own racing and rallying activities this year, Loeb's Sebastien Loeb Racing team is also running a European Le Mans squad.