I would like to express the following idea: the associations with which our association has a friendship with. But, I am not sure about the English phrase to use. Is it "Friend associations" of our association?
Okay, I'm guessing that this is in a business context?
"Business partners" or simply "partners" would be the most likely phrase, I think. It implies close cooperation, rather than friendship: but is often the most appropriate term for associations, rather than people.