DON"T CALL UA US CALL CENTER!!!! because they will tell you to wait 12 hours for Air china to respond their booking request. However, Air China will simply IGNORE the request made through UA North America Call center most time then cancel the request due to not ticketing immediately ! so you will never get a chance to ticket it!!!

Here is the procedures:

1 Call UA office in Shanghai/Beijing, tell them u want to book a CA ticket using UA miles. They will request seat for you and will hear respond from CA right the way-yes or no. If it is yes, they will give 2 record locators-one is 6 digits for UA, another one is 5 digits for CA.

2 Then CAll UA North America call Center RIGHT THE WAY and tell them the UA locator, now the agent will see confirmed and should be able to ticket the reservation!

3 DON'T forget to ask the 016 ticket number from UA

4 Call CA North America office during normal business hour and give ur 5 digits CA locater, you need to do a reconfirmation with CA again, they call them "RR"

5 Once you are in china, You need to call CA CHINA office to do a RR again for your return flight!!!! you cannot do it by calling CA north America call center.

6 If this is just a Intra china flight, call CA CHINA office to confirm.

UPDATE: If you ticket involves CA and UA, UA china office cannot do it for you, but they can set up a reservation for CA only. then u can add UA lag into that PNR when u ticket with UA North America Agent!

I just successfully ticketed a SFO-LAX-PEK-SFO on UA/CA C class using UA miles since no award seats on other *A partner C class available !!!