Glasgow recently served notice that it intended to leave Cosla next spring, but until now it took part in its proceedings.
But after Friday's vote, council leader Gordon Matheson said Glasgow would not have anything to do with Cosla.
It makes it almost certain that Glasgow will leave the organisation in 2015.
Matheson said: "Cosla has now run its course. It's now time for us to disengage from that organisation."
Glasgow is one of eight Labour-led councils to have given Cosla notice to quit since January.
Glasgow is now in talks with other breakaway councils about creating a stripped-down alternative body to Cosla.