The Star Alliance RTW (RWSTAR1) costs more than a two airline combination RTW. I would try and see if I could book an RTW on UA/CX, and then book a separate BKK SIN BKK ticket, as the total might cost less. I am not sure how many stopovers are needed on a two airline combination, but I think that you can do it with two. I would not do the "hidden city" routine, as the non-use of your first flight segment may cancel your onward reservation. Wil1408, you can E Mail me at [email protected] if you want to get some details of the UA/CX RTW.