Study to Evaluate the Efficacy and Safety of SLV306 in Subjects With Hypertension

Inclusion Criteria: * sitting office diastolic blood pressure between 90 and 109 mmHg * office systolic blood pressure between 140 and 179 mmHg * mean day-time diastolic 24-h ABPM blood pressure \>= 85 mmHg inclusive at baseline Exclusion Criteria: * known secondary hypertension * decompensated congestive heart failure