Chemical and paper company Aero Celje has become a 100% owner of Balkan, a Belgrade-based producer of glue, adhesive tape and detergents, the Celje-based company said. Balkan Beograd, which used to be part of the group Grmec, is a profitable company that employs some 100 workers. It is a very successful Serbian company, Aero stated in a press release.