Thanks for the comments. Have not gone into the ticketing yet, and will probably have to work within an economy fare. Sounds as if the best is to get the four airlines: AY,CP,CX & QF for the SIN/NRT return trip, then add a side trip on BA[KUL/CGK/KUL]or[HKG/MNL/HKG]. Was dreaming that if only I could get AA or BA, all five would fit into this one trip. Any advice on whether there yet is one-world substitutability on a return trip such as SIN/NRT? I may be trapped into one airline if I am pushed to get a discounted SIN/NRT/SIN fare.