Association has got two meanings - the 1st being:  
>"a group of people organized for a joint purpose". (For example,"The National Association of Probation Officers".) 

And the 2nd being:

>"a connection or cooperative link between people or organizations". (For example, "He developed a close association with the university".) 

Now, I hope you would be able to choose which one to use. If not, then "ABC is a ..." would be the best choice.