The caliper manufacturer always supplies the OEM pads but then uses one of their other brands for aftermarket parts: so all GTV rear calipers and OEM pads are ATe and fronts are either ATe, Lucas or Brembo depending on which calipers you have fitted.
The brand of pads used for OE will be decided on by the vehicle manufacturer & will not necessarily be manufactured by the brake manufacturer. Bear in mind that not every brake manufacturer manufactures friction materials & not every friction material manufacturer manufactures brakes!
The aftermarket's a jungle! Pads branded with the car or brake maker's name may not be the same as OE. Pads branded with the name of a friction material company may be someone else's product, as very often when you're supplying a niche model it's not worth tooling up for a pad so it's bought in from the vehicle's home market or the OE supplier.
Where are we going & why am I in this handcart?