Yesterday I booked a return ticket ATH-AMS for my wife through an OTA. On a single reservation/PNR it had KLM flights outbound and A3 flights inbound (Skyteam and *A).
I'm not entirely sure if the KLM segment fare is based on a roundtrip, possibly not - they may be two one-ways on a single reservation. However the ticket price this way was about 30 euro less than booking two one-ways separately (KLM one-ways are notoriously almost as expensive as roundtrips).
Anyway, what I'm wondering is: Would such tickets be upgradable? The reservation is made by a 3rd party, there are KLM segments and A3 segments. The KLM segment has a different eticket (074) than the A3 segment (390).
To me this implies that the eticket for the Aegean segment is actually issued by Aegean, and they should have full control over it for upgrades. But I'm not sure if they would want to touch such reservation at all. Any experiences?