The French firm made the shock announcement on Wednesday, signalling the end of its relationship with Nissan and the works NISMO team, which it has supplied continuously since the 2013 season.
A brief statement said that the decision was taken as a result of Michelin "reconsidering its race support structure".
Michelin clarified that its supply of the #23 NISMO and #3 NDDP Racing Nissan Zs, which sit first and second in the point standings, will remain unaffected until the conclusion of the current season.
The statement made no mention of plans to curtail its involvement in the GT300 class, where it supplies the Team Studie BMW M4 GT3.
Michelin's surprise withdrawal is set to leave SUPER GT's top class with three tyre suppliers in the form of Bridgestone, Yokohama and Dunlop for the first time since the 2008 season.
Yokohama, like Michelin, currently supplies two cars - the Racing Project Bandoh Toyota GR Supra and the Kondo Racing Nissan - while Dunlop supplies only one, the Nakajima Racing Honda NSX-GT.
Michelin has won four GT500 titles, two with the MOLA Nissan squad in 2011-12 and then two more in 2014-15 with NISMO.
Michelin’s departure has wide-ranging ramifications for both Nissan and the championship as a whole. Nissan has the headache of trying to reach an agreement with one of the three remaining GT500 suppliers, while the tyre war that has been a core element of the premier category for so many years now faces an uncertain future.
Realistically, NISMO will want to have its cars using tyres that the Nissan stable already has knowledge of. That narrows down the choice to Bridgestone and Yokohama, which currently supply Team Impul and Kondo Racing respectively.
Source: Autosport