Swiss driver Deletraz is also set to race for the Polish team in September Fuji’s round, as van der Zande will be away on IMSA WeatherTech SportsCar Championship duty with Chip Ganassi Racing.
The Portimao WEC race on June 13 falls on the same weekend as IMSA’s Detroit fixture, while the Fuji event on September 25-26 clashes with IMSA’s rescheduled Long Beach round.
For those events, ex-Formula 2 racer and one-time Rebellion LMP1 driver Deletraz will share Inter Europol’s Oreca 07 with Alex Brundle and Kuba Smiechowski.
“I am very happy to join IEC at Portimao and Fuji as Renger is busy with his IMSA commitments,” commented Deletraz. “I can already see the team is very motivated and pushing for good results. I’m looking forward to working with Alex and Kuba.”
Deletraz’s two planned WEC outings come on top of his full-time European Le Mans Series commitments with Team WRT. He and co-drivers Robert Kubica and Yifei Ye dominated last month’s Barcelona season opener.
The WEC Spa 6 Hours starts on Saturday May 1 at 1.30pm CET and will be streamed live on Motorsport.tv.