Plane do everything Pax/Baggage/Ramp and Dispatch as in full weight and balance.
The Passenger Handling and Dispatch was inherited from Aviance through TUPE.
Aviance in T1 still exists until October when the staff TUPE to Menzies.
I think EL AL and US Airways are handled bu United and the other contracts South African & Asiana (ramp only are out for tender)