The upcoming 12.04 release will be the last that the company supports financially.
The news was broken on Monday by Jonathan Riddell, a developer who is employed by Canonical and works on Kubuntu.
According to him, the distribution has not been a commercial success and that is the reason why Canonical has come to this decision.
Kubuntu will now become a so-called community distribution, with Canonical offering infrastructure support as it does for other recognised derivatives such as Edubuntu and Xubuntu.
The decision focuses attention on the fact that Canonical is a business first and foremost, looking to balance the books at least by the time it turns 10. Ubuntu was first released in October 2004.
Ubuntu 12.04, otherwise known as Precise Pangolin, is due for release in April. A second alpha version is available for testing at the known but there are problems with the installer, at least as of yesterday.