Hi MajorD,
I'm not an expert, but I guess you have a point. They could simply tell the investor that they had 100,000 ECU shares (but don't really) and now they have 5,000 AUM shares. However, what about the voting forms on the merger? Wouldn't most investors wonder why they were not allowed to vote, despite owning shares? I'm sure you don't get a voting form without producing some proof of ownership. At least that's how it works with my other shares...
...also there is the case of the small cash amount. It's not much money, but most shorters don't really like being involved where they have to pay out for something they don't have, which is why dividends are usually a good deterrent.
This is my limited understanding, but I will be approaching my Swiss bank on Monday to see how I proceed to a) ensure I have my voting card and b) get my AUM shares. If they are short, that might prompt them to some action ;)
Cheers
Soul