I booked a trip on the aa.com website flying MAA - HKG - LAX - PHL in the month of September. The flights from MAA-HKG and HKG-LAX are operated on Cathay metal. This was a very good fare at $648 for Economy!

However, I am unable to make seat assignments on the Cathay flights when I enter the Cathay PNR number. They point me to American as they issued the ticket. My Aadvantage number is listed on the reservation.

American says they have no insight into Cathay's seat assignment and ask me to talk to them. So in the end, both airlines point to each other! See screenshots.

I have status (One World Sapphire) which does give me access to pick exit row seats for free, but it doesn't help if both carriers point fingers at each other.

Strangely enough, I am able to make a meal reservation on the Cathay flights. The seat assignment is the problem.

Do you know how I can get this sorted out? I do not want to show up at the airport and get the dreaded middle row seat next to the toilet for the 13 hour trip to LAX...

Did you try calling Cathay and speaking to someone on the phone?

Yes I called Cathay. She initially said it was operated on AA metal and AA had to assign seats. When I corrected her, she said the seat map is "blocked" as it is an AA marketed flight.

This is frustrating. I know AA and CX are separate companies, but then why market such flights? I have no choice but to check in 24 hours and hope i can get a decent seat.

I would HUACA CX, or AA should be able to select the seat for you if you request a specific seat number.

Codeshare flights always make things complicated. Not CX and AA, but just sharing my experience on CX and JL codeshare.
I am OW emerald, should have access to all seats.

I had a JL code CX operated flight last week.
I called JL, I asked for window seat, they said the system assigned 62K (cannot change/choose)
I looked up my booking on CX website (same booking reference). All seats are shown as blocked except for 62K
I online checked in on CX website, the same seat map was showing and unable to choose other seats.
I called CX reservation (well, within 24 hrs of departure) and the phone staff helped me to choose seats further forward.
Note, I am not sure at which point CX takes over the booking (maybe when online check in starts?)

Conclusion: call CX

Strange. Don't know how it is for paid flights from a partner; but whenever I book CX flights using Alaska Airline miles, I can't select a seat until 48 hours before departure--and that's only because I'm Oneworld Sapphire and I get 48 hour check-in privileges. Some have to wait 24 hours before departure to choose their seats.

Have you called CX? Your Sapphire status gives you seat selection for free including extra-legroom ones.

I did. They told me that the flight was booked on aa.com, so AA has to assign seats. But AA tells me that the flight is operated by CX, so I need to contact them.. So frustrating!

Its good to know you get 48h checkin privileges. I hope this is the case with AAdvantage.

I�ve had Cathay Pacific customer service blame partner airlines before, saying they couldn�t do something because I booked on a partner. This happened to me yesterday and the CX agent was simply wrong. I asked to speak to a supervisor and then magically the problem was solved.

CX definitely can but many agents these days don't know what they are capable of. HUACA and/or ask to speak with supervisor like the poster above did.

Short update from my side. I called Cathay again but this time I asked to speak to a supervisor. She was able to assign seats based on my OW Sapphire status! Thank you all for helping me find a solution here!!

This one correct. HUACA whenever any CX agent attempts to get you to talk to AA. I'm doing to borrow Youtube Domix's language

"She is a liar. She lied to me. With her mouth, through the phone, and into my ear"