Main inclusion criteria:

• Out-patients
• Written informed consent
• History of atopic disease
• History of perennial bronchial asthma for at least 6 months as defined by ATS criteria
• Current use of only inhaled short acting beta-2-agonist as required (for at least 4 weeks prior to baseline period B0)
• Stable asthma, i.e. no exacerbation or relevant respiratory tract infection within 2 months prior to study start
• FEV1 ≥ 70% predicted
• Hyperreactivity to AMP (PC20FEV1 < 25 mg/ml)
• Good health with the exception of asthma
• Non-smokers as well as ex-smokers with either = 10 pack-years or more than 6 months of smoking abstinence

Main exclusion criteria:

• Concomitant severe diseases or diseases which are contraindications for the use of inhaled steroids (e.g. lung tuberculosis)
• Clinically relevant abnormal laboratory values suggesting an unknown disease and requiring further clinical evaluation
• Use of systemic steroids 4 weeks (injectable depot steroids 6 weeks) before entry into the baseline period, or more than 3 times during the last 6 months
• Pregnancy or intention to become pregnant during the course of the study, breast feeding, lack of safe contraception in heterosexually active female patients of child-bearing potential, or postmenopausal for less than one year
• COPD (i.e. chronic bronchitis or emphysema) and/or other relevant lung diseases
• Known or suspected hypersensitivity to inhaled steroids or to the other excipients of the metered dose inhalers
• Immunotherapy within one month prior to B0 and/or during the entire study duration