Originally Posted by
CopperSteve
Separate airlines should be fine. I once did EWR-PVG-EWR on CO and did a one-night trip PVG-NRT-PVG in the middle. Didn't think anything of it.
That routing wouldn't be a problem anyways. What you did is end-on-end ticketing and is, in the vast majority of fares, completely acceptable.
It is only a problem for the airlines when you nest trips to avoid fare rules.