There are two main ways in which horizontal mergers may significantly impede effective competition, in particular by creating or strengthening a dominant position:
(a) by eliminating important competitive constraints on one or more firms, which consequently would have increased market power, without resorting to coor- dinated behaviour (non-coordinated effects);
(b) by changing the nature of competition in such a way that firms that previously were not coordinating their behaviour, are now significantly more likely to coor- dinate and raise prices or otherwise harm effective competition. A merger may also make coordination easier, more stable or more effective for firms which were coordinating prior to the merger (coordinated effects). © EUR Lex
