Had a mate years ago that had all his quals but no NVQ, they wouldn't entertain it so he came back and did his 2356 (sparky NVQ) and went back and I haven't seen him since, so he either made it, or he's lying somewhere very sunburnt.
i would imagine the qualifications held are compared to that of their own standard, last time I checked a fully qualified uk electrician has one of the highest ranks in this situation.
another old work coleague of mine did 1 year in Oz and 5 in New Zealand. Both for fire and security companies, and he had no Qualifications at all, not even time served.