Taking that back a step to a more "micro" level would a company be willing to temporarily hand over unfettered control of one of it's multi,multi million pounds assets to a controller working for another company sitting in another part of the world?
Funnily enough I was pondering this only yesterday.
It seems to me that companies already do, to a certain extent - ATC are a fairly vital part of the safety chain, so right now another company (NATS) in another part of the world is a large part of the control of many overseas airlines' assets.
It seems to me a logical way to organise pilotless aircraft would be simply to give Air Traffic Control even more Control. I.e. the ground-based pilots tasked with intervening in an emergency that the automatics can't handle would work for and alongside ATC for that airspace. (The question of who does the job in uncontrolled airspace is left as an exercise for the reader.)
Do I think it's likely, in my lifetime? Not really. But it's certainly possible. Precedent effectively exists in realms such as the railways, where the infrastructure/signalling/automatic train operation (where relevant) etc. are operated by different companies to the actual train operators - so I don't see organisational issues as insurmountable.
(Not advocating that approach incidentally, merely throwing it out there as one possible way things could be organised.)