The bombshell news is expected to be confirmed today with Warburton stepping down from the CEO role less than a year into his latest tenure.
He will be replaced as CEO by Nettlefold, who is already the Chairman of Racing Australia Consolidated Enterprises, which owns Supercars.
Details of the split between Warburton and the series are yet to fully come to light.
More to follow
This article first appeared on Speedcafe.com, a sister site to MotorRacing.com.