About 75 million speakers of french language exist in the 39 countries and they have made french as their official business language as its a part of the united nation and the world trade organization and many member countries of the world share this language.
While English is considered as the link language of all world nations as this language, Similar to mandarin is important to China, and it will continue to grow in the coming ages.
As most of the Asian and the European nations speak English they preferred a way of dealing is in terms of the English level of business. Is there more than 6000 languages in the world thus it's difficult to keep connect and English is appropriate for business.
