Glasgow / EGPF
Swissport
Air Canada Rouge
Air France
Air Transat
Albastar
American Airlines
Austrian Airlines
BH Air
Blue Air
Delta Airlines
easyJet
Emirates
Eurowings
KLM
Lufthansa
Ryanair
Thomas Cook Airlines
United Airlines
Virgin Atlantic
Wizz Air
Menzies
Aer Lingus Regional
British Airways
Flybe
Icelandair
Jet2 (Underwing only)
Loganair
Thomsons
Westjet
The only ones not mentioned are cargo and eastern. I'm not 100% on cargo but pretty sure most/all (except BA) are swissport. Eastern is swissport for the IOM flight (until it becomes flybe I guess) Menzies for their flybe flights.
Any mistakes or missed airlines let me know.