Originally Posted by
frankvb
I am under the (perhaps incorrect) impression that you can't add another ticket to a PNR once it is established - in particular as you will then suddenly create things like being protected in case of delays without actually buying all flights on one ticket (but maybe I am completely wrong here and the protection is only valid for flights on the same ticket, not the same PNR). And mentioning expedia made me think it would be pretty difficult to get anything out of the ordinary done with them. But by all means give them a call and check if it is possible.
You can add flights to the same PNR after the tickets are issued. As for the protection in case of a delay or cancellation: strictly by the book, you are not protected. However, often the CS will protect you on an alternate flight when they see you are on a connection in the same PNR. They are not required to, though.