Aside from UK, under Northern stars the game looks like this;
Helsinki Ground Handlers;
Norhtport (100% Finnair owned)
Finnair
Aero Airlines AS
CSA
British Airways
Aeroflot PAX flights
Pulkovo
Lithuanian
City Airline
SN Brussels Airlines
Cargolux
UPS
Penauille Servisair Finland (Independent from carrier ties)
LOT Polish airlines
Aeroflot Cargo
KLM
Air Berlin
Germanwings
Turkish Airlines
DHL
Rafavia
Air Finland
Britannia Nordic (Tuifly, BLX)
+ many daily adhocs incl business flight ramp services
SAS ground services Finland 100% SAS owned
SAS
Blue1 (KF)
Lufthansa
Tyrolean
Baltic
Eurocypria
Interhandling
Finncomm (FC)
Airpro
Mytravel
Flyme (only occasional adhocs anymore)
Karthago
Two first mentioned handling companies offer de-icing services to customers, Penauille Servisair also to Northport handled Aero and SGS handled Lufthansa.