In general, discrimination against trading partners who are in a competitive relationship can only be considered abusive if the conduct of the undertaking in a dominant position leads, in the light of all the circumstances of the case, to a distortion of competition between those trading partners. Preferential tariffs, in particular for customers of undertakings belonging to the same group, or price lists imposing unjustified differences in treatment are an abuse of a dominant position. It is irrelevant, however, that the application of the new price scale does not disadvantage the complainant who, because he did not reach the required threshold, would not have obtained the quantity discounts provided for, since the discrimination must be assessed with regard to the price scale itself, independently of the previous situation. In order to be considered abusive, a practice of price differentiation must concern purchasers in a comparable situation and create a competitive disadvantage. A practice of price differentiation between “on net” and “off net” calls which is not objectively justified either by differences in call termination charges or by internal transfer costs constitutes an abuse of a dominant position.

According to the Competition Authority, the concept of discrimination should not be confused with that of inequity: when a dominant company issues discriminatory rules, these rules only harm a limited number of its customers – those who are discriminated against – while when it imposes unfair trading conditions, they have broader effects as they are likely to apply to all customers. Indeed, the definition and application of unfair trading conditions are likely to affect the normal functioning of the entire market on which the dominant undertaking operates, when the latter enjoys a monopoly, has extremely high market shares or occupies an “extraordinary” dominant position.