ABIDJAN (Reuters) - Ivory Coast's economy, French-speaking West Africa's largest, is expected to grow by an average of 7.4 percent between 2017 and 2020 after reaching 8.5 percent this year, the International Monetary Fund said on Friday. The GDP of the world's top cocoa grower expanded by 8.6 percent in 2015, the IMF said in a statement, repeating a figure that is significantly below the 10.3 percent announced by President Alassane Ouattara in March. (Reporting by Joe Bavier; Editing by Mark Trevelyan)