The importance of the research is determined by the necessity to find adequate methods to assess and develop Management B.A. program students’ oral mediation competence in English. The issue is vitally important for both students and teachers. For students, because mediation skills can be treated as part of «soft skills», which have recently become so attractive for the employers. For teachers, mediation is a new concept in the paradigm Reception - Production - Interaction – Mediation introduced by The CEFR Companion Volume (2017). We consider both cognitive mediation and relational mediation in a monolingual interactional aspect. Mediation skills are checked in the format of a professional discussion. The purpose of the research is: to work out an overall scheme for teaching and testing mediation competence in oral professionally-oriented performance at B2 level of English in accordance with CEFR descriptors and local educational needs; to pilot it and finally to analyze testing scores statistically. The data show that the teaching materials prove to be effective and lead to the improvement of testing results. The scales are validated and reliable for the population of the experiment which is representational for the focus group. The scheme developed may be used for the departments of Management in tertiary education as well as be adapted for other professionally-oriented profiles and languages other than English.