Asthmatic children who remain symptomatic on inhaled corticosteroids (ICS) require an adjustment of their asthma therapy. Current guidelines suggest that the treatment options are either an increased dose of inhaled corticosteroid or the addition of other therapy such as a long-acting beta-agonist (LABA). In the paediatric age range, major concerns with respect to high dose ICS therapy are growth retardation and the suppression of the hypothalamic-pituitary-adrenocortical (HPA) axis. Previous studies in adults have shown that a combination product that included a LABA as well as the ICS allowed to reduce the steroid dose and was still at least as effective in achieving asthma control as treatment with a higher dose of ICS. These treatment options shall be compared in the present study. Children who remain symptomatic while inhaling 100 µg fluticasone (FP) twice daily shall be randomised to receive the salmeterol/ fluticasone combination product, Viani (SERETIDE) 50/100 µg, or fluticasone 200 µg as a comparator drug, inhaled twice daily via the DISKUS for a period of eight weeks.