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 one and two 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.
Bridgestone currently supplies the majority of the 15-strong GT500 field, expanding to 10 cars this season following the ARTA Honda squad adding a second car to its stable over the winter.
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.
Bridgestone last supplied the works NISMO team in 2012, before the decision was made by the team to return to Michelin after a single season using the French firm's products in 2010 (the result of it slimming down to three cars amid the financial crisis).
Michelin has won four GT500 titles, two with the MOLA Nissan squad in 2011-12 and then two more in 2014-15 with NISMO.
Outside of the Nissan camp, it has also supplied the Dome Honda and SARD Toyota squads in the past, while it also enjoyed a partnership with the TOM'S Toyota team between 1999 and 2003.
