This trial is conducted in Africa and Middle East. The objective of the study is to compare glycemic control of Biphasic insulin Aspart 30 twice daily with Biphasic insulin Aspart 30 twice daily plus Insulin Aspart, both insulin treatments with or without metformin, in subjects with type 2 diabetes, previously treated with Biphasic Human Insulin 30/70.

Inclusion Criteria:

• Type 2 diabetic subjects
• Current treatment with Biphasic Human Insulin 30/70 twice daily alone or in combination with any oral hypoglycaemic agent for at least 3 months prior to entering the trial
• HbA1c at least 12%
• Willing and able to perform self blood glucose monitoring (SMBG)

Exclusion Criteria:

• History of drug or alcohol dependence
• Receipt of any investigational drug within the last month prior to this trial
• Anticipated change in dose of prescription medication, which may influence glucose regulation (Mono Amino Oxidase-inhibitors, non selective beta-adrenergic agents, anabolic steroids and systemic glucocorticoids)
• Severe uncontrolled hypertension
• Recurrent severe hypoglycemia as judged by investigator
• Any disease or condition, which the Investigator feels, would interfere with the trial