The acquisition of a minority interest, with or without a blocking minority, is likely to result in a concentration. It is necessary, however, that a stable majority is able to be achieved. A piecemeal majority does not allow a presumption of joint control by the minority shareholders. Decision-making practice infers the existence of a decisive power of influence from a body of converging indicators, such as veto rights, blocking minorities or shareholders’ agreements, the possibility of appointing managers within the target, the dispersion of the other shareholders, the existence of significant links or significant intervention as a lender to the undertaking. The competition authorities seem to consider that a mere creditor situation could, in certain circumstances, suffice. The significant influence used in matters relating to consolidated accounting cannot be equated with decisive influence.