The Federation of Astronomical Societies (FAS) is an international union of astronomical societies formed in 1974. Its motto is "Supporting UK Astronomy", and there is also one member society from Spain. As of August 2014, it has 205 member societies.
FAS publishes a newsletter 3 times a year, which is sent to its member societies, and holds an annual convention. FAS is run by a council of elected volunteers.
References
Federation of Astronomical Societies Wikipedia(Text) CC BY-SA