Originally Posted by RWY02KTM
There is another theread
here , discussing this issue. Looked like changing from SQ to TG meant it was a re-issue. This was e-tix though. With paper ticket, it should be possible to do without a re-issue.
OTOH, to the OP, If you do have to re-issue, Why not go HKG-BKK-BOM (TG), or HKG-ICN-BOM (OZ). but this definitely means a ticket re-issue and re-routing.
UA claims they will charge USD 125 as the original routing is not on a UA flight/codeshare.
HKG-ICN-BOM won't work as OZ flies ICN-DEL, not daily tho'.