What is the nature of this agreement? Is it a lease, as it refers to a private company making use of public infrastructure. Would that be a lease? The word "convention is used" which is not to my mind a lease per se. It is in my view a "contract":
https://www.editions-tissot.fr/droit-travail/dictionnaire-dr... It's referring to "lieux mis à disposition" which is likely to refer to some more than just a property but in this case an area which is in the public space (say a terrace for a café). If this were the case there would be definitions of use in terms of keeping the area clean, seating capacity etc.
I think the "premises made available" would be acceptable. If you use the term "leased premises" you are changing the nature of this agreement. I think it is more important to use a term that may not sound natural in English and have that questionned, than use an English term that sounds natural but may change the integrity of the document.