The aim of the study is to compare the efficacy of ciclesonide versus fluticasone propionate on lung function, symptoms, and use of rescue medication in children with persistent asthma. Ciclesonide will be inhaled at one dose level once daily; fluticasone propionate will be inhaled at one dose level twice daily. The study duration consists of a baseline period (2 to 4 weeks) and a treatment period (12 weeks). The study will provide further data on safety and tolerability of ciclesonide.