In reply to timmyhobby:
Hi,
In my experience of taking numerous groups bouldering in Font (corporate groups whilst working out of the INSEAD Business School) and also paddling trips to the French alps, there are a few considerations.
If the business was generated and invoiced etc in the UK (i.e UK clients and you are a UK company) then it is often ok, as not seen to be taking French business
As often the way, any laws etc are open to interpretation, for example French guys who I work with suggested we would be ok bouldering because we were doing a Corporate team build rather than a sporting activity, similar concept if it is a school group.
If you are in a very busy area where a lot of guides work it might be different but I would imagine they would be more interested in the alpine work.
Sorry if that seems a bit vague, but it is is!! PM me if you want some more info (if it is specifically Font I have some good French contacts there, same for Targasonne).