Originally Posted by Jasper2009

If a ticket involves multiple airlines, it is quite common that each airline has a different PNR, especially if thoe airlines use different reservation systems (e.g. Amadeus, Sabre etc.)

What is always the same is the ticket number.

You should be able to access the reservation on the UA website using the ticket number (014xxxxxxxxxxx) and in turn see the six digit alpha-numeric UA booking reference)