Comparative Study of HOE490 O (Glimepiride and Metformin) Compared With Placebo on Top of Glimepiride

Inclusion Criteria: * Type 2 Diabetes Mellitus patients treated with constant dose of glimepiride on top of diet and exercise * Patients who gave informed consent to participate in the study Exclusion Criteria: * Patients with HbA1c of \< 7.0 % and \> 11.0 % * Patients with any following laboratory test abnormality : * ALT and/or AST: \> 3 X ULN * Neutrophils: \< 1,000/mm3 and/or platelets \< 100,000/mm3 * Hemoglobin: \<11 g/dL * Creatinine: \>= 1.3 mg/dL in case of male or \>= 1.0 mg/dL in case of female The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.