QNH1013, it's all charter.
Those labeled Premiair are based in Copenhagen and they mostly fly from Scandinavia to more sunny places.
Those labeled Airtours do the same, mainly from Britain.
Some day the name Premiair may disappear. But the travel agencies behind Premiair try their best to assume a "Scandinavian identity" even if they are totally British owned by Airtours.
Their competitors are mostly Danish, and it would be a promotional disadvantage to tell the world that "we are the foreigners".
Rgds, Preben Norholm
Always keep your number of landings equal to your number of take-offs