I would be inclined to feel that other than the graduates of the Ivy League Universities (eg Oxford, Cambridge, MIT, Havard), graduates from other universities (local or overseas) are given more or less the same opportunities.
Nowadays the degree is so common that it is more like a "minimum requirement" thing. As long as you are a graduate from a recognised university, and you meet the requirement, you'll probably be considered for the job interview, which is the deciding factor whether you get the job or not.
For example, in the case of an accountant position in SIA, I understand that their minimum requirement for the interview is a 1st Class Hounours degree in Accounting. From my understanding there is no discrmination as to where that degree comes from (so long it is recognised by the company). The papers only certify that you are qualified to handle the job; your character and attitude are the qualities that will get you the job.
It is also widely regarded that overseas graduates are more independent, responsible and have better interaction skills than local counterparts. I suppose these would be added "pluses" that will help during the interview, but they are just factors and not deciding factors. After all, how can one tell that the interviewee is responsible until you have assigned him/her with the job? It is quite interesting to note that doing well academically does not really mean doing well in a job (something like IQ vs EQ).
Anyway, just some personal opinions from an undergradute from an overseas university who has never applied for a job before.

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I do not embrace my dark side, but I do acknowledge it;
else I can never be whole