If a company hires you it wants to get a return on its investment, obviously, when you're talking about $60K for a type rating. No good spending that kind of money on someone who is going to retire in a couple of years!
I believe the cutoff for the N Sea, at least (my expertise is with helicopters), is around 42. But then, that may not apply in the airline world. However, it wouldn't surprise me if it does.