I have tried to get a first class seat in November on SQ from FRA to SIN with UA miles.

SQ reservations says they have 1 "O" (free first) seat on the particular flight, but UA has none.

One UA agent told me the advantage of the Star Alliance is that all partners have equal access to the same inventory.

Another UA agent told me that the individual partner airlines can allocate inventory just for their own members.

Who is correct? Wouldn't SQ have a different booking code for their own members?

I will post on UA and STAR forums to try and get as many opinions. Apologies for the dupes.

Thanks.