Type 2 diabetes mellitus is a metabolic disorder that is primarily characterized by insulin resistance, relative insulin deficiency, and hyperglycemia. People with type 2 diabetes are at high risk of many serious diabetic complications, including cardiovascular disease, blindness, nerve damage and kidney damage. Balaglitazone is a thiazolidinedione derivative that is being developed as an oral anti-diabetic drug to improve blood glucose control in patients with type 2 diabetes. The purpose of this study is to assess if additional treatment with balaglitazone in patients with type 2 diabetes on stable insulin treatment will improve blood glucose control and decrease the daily insulin dose compared to placebo, but with less impact on weight gain and oedema than pioglitazone (Actos®) 45 mg.