Business English is English especially related to international trade. It is a specialism within English language learning and teaching; for example, the teachers' organisation IATEFL has a special interest group called BESIG http://www.besig.org. Many non-native English speakers study the subject with the goal of doing business with English-speaking countries, or with companies located outside the Anglosphere but which nonetheless use English as a shared language or lingua franca. Much of the English communication that takes place within business circles the world over occurs between non-native speakers. In cases such as these the object of the exercise is efficient and effective communication. The strict rules of grammar are in such cases sometimes ignored, when, for example, a stressed negotiator's only goal is to reach an agreement as quickly as possible[1]. (See linguist Braj Kachru's theory of the "expanding circle".)
It is possible to study Business English at college and university; institutes around the world have on offer courses (modules) in BE, which can even lead to a degree in the subject[2].
The City and Guilds of London Institute offer International Business English examinations.