Well the question is quite simple... I am going to finish my PhD in finance and tax law this year and I do not want to work in a law firm but rather for investment funds, banks etc. (not in the legel department...) . As I have put a considerable amount of time and energy into my phd I would like to start working but I am still not confident if my PhD in law would qualify me for such types of work. Some say that after a law degree and a PhD I have good starting requirements because of my knowledge in an important field and the analytical skills that you need to conduct your phd research. Others say that it is highly unlikely to do anything without a MBA because my first degree is in law.
Well any input is really appriciated...

Do you have strong quantitative skills? If not, I don't see what sort of non-legal work you would be qualified to do excellently.

It would be a transition, that's for sure. Although if you've been working on finance and tax issues, at least you'd have a conception of what happens in these fields, which is more than many have. But Duncan is right, if you don't have great quant skills these roles are not exactly easy to get into. An MBA would help with these, as it would with the networking and the career searching that you'd inevitably need to do.