Hola Isabela,

As far as I know, there aren't many options for part-time legal studies or distance learning in Geneva. The only one I know of is the University of London LL.M. ( distance learning) which a friend is doing. Their open day was in May but perhaps you may find some interesting info and contacts on the link below.

That said, the tuition fees in Geneva are much cheaper but don't cater much to persons who work and study. Good luck!

http://www.londoninternational.ac.uk/swiss/index.shtml

What do you mean by re-take? Have you already got a qualification in law? 

If so, why don't you think about doing an LLM - the University of Geneva offers quite a few options, as does the HEI (though theirs are mostly international law). 

In my experience, graduate qualifications are generally more helpful towards people who are working alongside their studies. 

I'll add a question: Should it be in English or is French ok?

For international trade law, the Mile programme of the WTI in Berne is really recommendable:

http://www.wti.org/

In Geneva, I've heard good things about the Graduate Institute: 

http://graduateinstitute.ch/