From what I know, Niki Lauda doesn't own anymore any of his companies.
Lauda Air A/G based in Austria is totally owned by Austrian Airlines Group.
Lauda Air Italy based in MIlan MXP is now 100% part of the Livingston Aviation Group (The airlines division of the second largest Italian tour operator).
Niki Lauda is still vice president, but with 0% share.
Livingston Aviation Group owns also the charter airlines called Livingston that now flies 3 A321. When SALE will deliver the 3 A332 to Lauda Air Italy in the next months they will paint in Livingston livery and the Lauda brand will disapear from Italy.
That's what I read on an airticle on a French web site a while ago.
Nothing I could find on their web site, cause the English version is not updated since May.