Robert Wickens will return to single-seater racing in 2018 in the Verizon IndyCar Series with Schmidt Peterson Motorsports, ending a six-season stint in DTM with Mercedes.

Wickens rose through the junior single-seater ranks before making the switch to DTM in 2012 with Mercedes, where he has won six races and recorded a highest finish of fourth in the drivers' championship.

The Canadian tested an Indy car earlier this year with Schmidt Peterson Motorsports as part of a ride-swap with compatriot James Hinchcliffe, who races full-time for the team in IndyCar.

Wickens was called on a second time at Road America when Mikhail Aleshin's visa was delayed, appearing in Friday practice, only for the Russian driver to return for the remainder of the weekend.

Wickens will now make the move across to IndyCar full-time for 2017 with SPM, marking his first campaign in single-seaters since his victorious Formula Renault 3.5 title bid back in 2011.

"It's been the most amazing six years. Until this season, I'd never really considered leaving Mercedes or the DTM," Wickens said.

"But first off, I can't thank Mercedes enough for the last six years and wish them the best of luck for the future. It's probably been the best six years of my entire life.

"I've had a lot of ups and downs on the way but never had so much support from a team before. It's been an honour to represent the brand and maybe it's not the last time.

"It's going to be a very steep learning curve [in IndyCar]. A lot of things will be completely new to me. I've never driven on an oval before. As everyone knows, I haven't been driving formula cars over the last six years since I've been in the DTM, so I have to get up to speed very quickly but am looking forward to the new challenge."

Mercedes will leave DTM at the end of the 2018 season ahead of its planned entry to Formula E in the autumn of 2019.