This is an 80-week extension to a study to assess the safety and effectiveness of vildagliptin, an unapproved drug, compared to rosiglitazone in lowering overall blood glucose levels in people with type 2 diabetes who have not previously been treated with drug therapy to lower their blood sugar. The purpose of the extension study is to gather data on the long-term safety and effectiveness of vildagliptin in people with type 2 diabetes.

Inclusion Criteria:

• Only patients successfully completing study CLAF237A2327 are eligible
• Written informed consent
• Ability to comply with all study requirements

Exclusion Criteria:

• Premature discontinuation from study CLAF237A2327
• Other protocol-defined exclusion criteria may apply