Inclusion Criteria:

1. Mild-to-moderate hypertension defined as a mean seated diastolic blood pressure of greater than or equal to 95 mmHg and less than or equal to 109 mmHg, measured by manual cuff sphygmomanometer at Visit 2.
2. 24-hour mean DBP of greater than or equal to 85 mmHg at Visit 3 as measured by ABPM.
3. Age 18 years or older.
4. Ability to stop any current antihypertensive therapy without risk to the patient (investigator's discretion).
5. Ability to provide written informed consent in accordance with GCP and local legislation.

Exclusion Criteria:

1. Pre-menopausal women (last menstruation approximately less than or equal to 1 year prior to signing informed consent) who:

   • Are not surgically sterile
   • Are nursing,
   • Are of child-bearing potential and are NOT practicing acceptable methods of birth control, or do NOT plan to continue practicing an acceptable method throughout the study. Acceptable methods of birth control include intra uterine device, oral, implantable or injectable contraceptives.
2. Night shift workers who routinely sleep during the daytime and whose work hours include midnight to 4:00 A.M.
3. Mean sitting SBP greater than or equal to180 mmHg or mean sitting DBP greater than or equal to 110 mmHg during any visit of the placebo run-in period.
4. Known or suspected secondary hypertension (i.e., pheochromocytoma).

5. Hepatic and/or renal dysfunction as defined by the following laboratory parameters:

   • SGPT (ALT) or SGOT (AST) > 2 times the upper limit of normal range.
   • Serum creatinine > 2.3mg/dL (or > 203 micromol/l).
6. Bilateral renal artery stenosis, renal artery stenosis in a solitary kidney, post-renal transplant patients or patients with only one kidney.
7. Clinically relevant sodium depletion, hypokalaemia or hyperkalaemia.
8. Uncorrected volume depletion.
9. Primary aldosteronism.
10. Hereditary fructose intolerance.
11. Biliary obstructive disorders.
12. Congestive heart failure (NYHA functional class CHF III-IV).
13. Unstable angina within the past three months prior to start of run in period.
14. Stroke within the past six months prior to start of run in period.
15. Myocardial infarction or cardiac surgery within the past three months prior to start of run in period.
16. PTCA (percutaneous transluminal coronary angioplasty) within the past three months prior to start of run in period.
17. Sustained ventricular tachycardia, atrial fibrillation, atrial flutter or other clinically relevant cardiac arrhythmias as determined by the investigator.
18. Hypertrophic obstructive cardiomyopathy, aortic stenosis, haemodynamically relevant stenosis of the aortic or mitral valve.
19. Patients with insulin-dependent diabetes mellitus whose diabetes has not been stable and controlled for at least the past three months as defined by an HbA1C greater than or equal to 10%.
20. Patients who have previously experienced symptoms characteristic of angioedema during treatment with ACE inhibitors or angiotensin II receptor antagonists.
21. History of drug or alcohol dependency within 6 months prior to start of run in period.
22. Concomitant administration of any medications known to affect blood pressure, except medication allowed by the protocol.
23. Any investigational therapy within one month of start of run in period.
24. Known hypersensitivity to any component of the formulations.
25. Any clinical condition which, in the opinion of the investigator would not allow safe completion of the protocol and safe administration of trial medication.
26. Inability to comply with the protocol.