Dogleg,
I can't speak for Canada but in the UK the new age discrimination legislation (I believe it started in October last year) apparently prevents any company from setting a compulsory retirement date. In other words, you now have to let the
employee decide when he or she retires.
If Cathay has a base in the UK then it will have to comply with the same legislation. It can no longer force its UK pilot workforce to go at 55 or even 60 (I'm assuming that's what it used to do).
UK based airlines are able to require retirement at 65 only because the CAA will not grant a medical for commercial flying past that age. Of course, if they could be persuaded to change, we'd all be flying till we're 80!
All the best
Overflare