Here are my observations, make what you will, I don't seek to offend anyone. I agree that there seems to be some kind of preference involved.

Local grads are great hires, but at the end of the day if your client base is in the UK or the US, do you think the firm will prefer that you studied in the UK with some knowledge of English law, or Singapore with no knowledge of English law? Let's leave aside where you trained (UK, US or Singapore) for a moment.

Sure you might argue that the UK bar is the biggest leveller of the playing field but it's also the fact that you'd have spent 3 years learning UK law prior to getting UK qualified vs 1-2 months at Bar school without learning UK law.

And to add that to the mix, the international firms have partners from the UK and US. Who would fit more?

Local grads are definitely not disadvantaged in terms of calibre, but it's just that the composition of the international firms stack the odds in favour of an overseas grad. You might think that the Singapore partners should determine recruitment, but no, in most setups it's the overseas HQ of that firm that usually makes the call. Where did those partners study? Probably Ivy, Oxbridge, other feeder schools.

There'll also be some from the 'delisted schools' some pricks on this forum keep deriding based on a misguided sense of intellectual sword waving. It doesn't matter at all.

In the international firm scene, the biggest glass ceiling is that they value having trained/worked at the Magic Circle/Skadden Arps/Latham etc more than anything. You don't even need a law degree to join a Magic Circle, train there, get qualified and then transfer to the Singapore office - you'll be more valuable than anyone else.

No one cares if you did a science or engineering degree even. It may even be an advantage if you do biology, get qualified, and join the IP patents team which has the big pharma companies as clients.

My qualifications: There are some exceptions. One of them is arbitration. If you do international arbitration and in particular, with a top rated team, it doesn't matter where you train at. Some of the SG firms have very good arbitration practices. Everything else the preference seems to run this way -

Magic Circle/top US > Silver > A&G > Other big 4