The Nissan DPi is set to exit the IMSA SportsCar Championship field following CORE autosport's decision to cease its programme at the end of 2019.
CORE had stepped up from the one-make LMPC division to the then-unified Prototype class in 2018 with an ORECA LMP2, with team founder Jon Bennett and driving partner Colin Braun winning two races at Mosport and Road America en route to second in the standings behind Action Express Racing duo Felipe Nasr and Eric Curran.
Having originally planned to stay in the newly-separated LMP2 division, the team made a late decision to take over the Nissan DPi project in 2019 after Extreme Speed Motorsport, which ran the Nissan Onroak DPi in 2017-18, closed its doors.
But Braun and Bennett have struggled for competitiveness so far this season, having taken a best result of fourth in the season-opening Daytona 24 Hours where they were joined by Romain Dumas and Loic Duval.
Bennett announced ahead of this weekend's GT-only IMSA round at Virginia International Raceway that he was stepping down from driving duties.
He wrote: "The 2019 Petit Le Mans will be my last race in a DPi. In fact, I have no racing plans of any kind in the near future.
"But, for those who know the power of being passionate, I will leave the door slightly ajar.
"The obvious question is why? The time has simply come for me. I have lived the dream of so many who are passionate about motorsport and it's time to reflect and enjoy racing, once again, from outside the racecar."
The announcement is likely to signify the end of Nissan's presence in IMSA's top class.
Its arrangement with ESM had been closer to a pseudo-customer deal than a full factory supported entry, and it is understood to have shown little interest in supporting CORE's effort.
CORE will continue to operate Porsche's GT Le Mans programme next year with the all-new 911 RSR-19, which will make its race debut in the World Endurance Championship curtain raiser at Silverstone next weekend.