T-systems Limited
Ownership
T-systems Limited is ultimately owned by Deutsche Telekom .
Also owned by Deutsche Telekom
T-Home 
Ben NL 
Crnogorski Telekom Similar companies
In Mobile Networks, under different ownership.
Sources
- T-SYSTEMS LIMITED — GLEIF
Who really owns the brands you use
T-systems Limited is ultimately owned by Deutsche Telekom .
In Mobile Networks, under different ownership.