This is an exploratory investigation of safety, pharmacokinetic (PK) and pharmacodynamic (PD) effects of BAY59-7939 with multiple oral doses of 10 mg, 15 mg and 20 mg once daily (od) in Japanese subjects with non-valvular atrial fibrillation (originally described in Japanese).

Inclusion Criteria:

Japanese subjects with non-valvular AF who met all of the following criteria:

• Male subjects aged 20 years or older and postmenopausal female subjects
• Subjects with persistent or paroxysmal non-valvular AF with >/=2 episodes before enrollment, at least 1 of which had been verified by ECG recording within 4 weeks before randomization
• Subjects who were at risk for stroke as follows:
• Subjects with at least one risk factor for thromboembolism (hypertension, diabetes mellitus, coronary artery disease, congestive heart failure).
• Subjects aged 60 years old and above regardless of the existence of above risk factors.

Exclusion Criteria:

• History or presence of stroke or transient ischemic attack.
• History of intracerebral hemorrhage.
• History or presence of bleeding at randomization; intraocular or gastrointestinal bleeding within the last 6 months prior to randomization.