The study population will consist of approximate 736 male and female adults (age 40 years and greater) with a clinical diagnosis of stable COPD [GOLD (2010)] and a smoking history of at least 10 pack years. It is anticipated that approximately 981 patients will need to be screened in order to randomize 736 patients into 2 treatment arms of the study with an equal randomization ratio, meaning QVA149 (368 patients), fluticasone/salmeterol (368 patients). Treatment randomization will be stratified by current/ex-smoker status and prior ICS use. It is intended that 552 patients will complete the study at Week 26 without major protocol deviations. Dropouts will not be replaced.