An extract from The Dominance and Monopolies Review - 7th edition
Market definition and market power
The criteria used by the NMCC to define the relevant market are practically identical to those described in the Commission Notice on the definition of the relevant market and applied by the Commission in its decisional practice. In fact, according to well-settled decisional practice, the provisions of the Notice are fully applicable to Article 2 of the LDC cases. No formal provisions exist in Spanish law or in the 'soft law' regulating market definition. Although the NMCC is often not very detailed in justifying its specific choice of market definition, this tendency is changing, and its analysis is progressively becoming more sophisticated and grounded in economics.
Given the lack of a provision defining 'dominant position', this task has been carried out by the NMCC, which, since 1999, has interpreted this notion in line with EU case law. Indeed, in 1999 the NMCC established that such a position exists when an undertaking has a sufficient degree of economic power and independence in the market to enable it to modify prices or commercial conditions, or both, without taking account of the reactions of competitors or consumers. This definition has been repeated by the NMCC, with small variations, in its more recent decisions.
The specific criteria used by the NMCC to assess dominance are very similar to those used by the Commission. For instance, in Bacardí, it was stated that to establish dominance it is necessary to focus on both the structure of the undertaking concerned (resources and methods of production, methods of presentation, transport and sales, technology and vertical integration) and the competitive environment (number and strength of competitors, market shares and sales volumes, prices and barriers to entry). In McLane/Tabacalera, however, it was established that the Bacardí criteria constitute the basis of a 'structural' approach, and that account may also be taken of behavioural elements and of the relationship between clients and providers and the undertaking in question.
Finally, it is noteworthy that the NMCC interprets Article 2 of the LDC, which refers to '[a]ny abuse by one or more undertakings', as empowering it to pursue the collective abuse of a dominant position.