Originally Posted by
JMBResona
I don't think two tickets -- one purchased from AA and another purchased from AY -- can be in the same PNR unless and until AA takes over the AY ticket due to IRROPS.
It absolutely can be. I have had multiple oneworld carrier issued tickets in a single PNR on many occasions. It's possible to also mix award and commercial tickets in the same PNR of any oneworld carrier combination, eg. AA award + AY commercial ticket. As a result I've often had PNRs with more than 20 flight segments.