Main Inclusion Criteria:

• During the last 4 weeks prior to baseline, treatment with an inhaled steroid (dosage: up to 250 mcg fluticasone propionate or equivalent)
• FEV1 80 - 105% of predicted
• Healthy with the exception of asthma
• Written informed consent has been obtained
• Outpatients
• Patients who have a history of persistent bronchial asthma for at least 6 months

Main Exclusion Criteria:

• Concomitant severe diseases or diseases which are contraindications for the use of inhaled steroids
• Concomitant COPD (chronic bronchitis or emphysema) and/or other relevant lung diseases causing alternating impairment in lung function
• An asthma exacerbation or an infection of the lower airways prior to entry into the baseline period
• Pregnancy
• Intention to become pregnant during the course of the study
• Breast feeding
• Lack of safe contraception
• Patient is current smoker with 10 or more pack-years
• Patient is ex-smoker with 10 or more pack-years